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Saturday, July 6, 2024

Obsessive–compulsive disorder

Obsessive–compulsive disorder
Frequent and excessive hand washing occurs in some people with OCD.
SpecialtyPsychiatry
SymptomsFeel the need to check things repeatedly, perform certain routines repeatedly, have certain thoughts repeatedly
ComplicationsTics, anxiety disorder, suicide
Usual onsetBefore 35 years
Risk factorsGenetics, Biology, Temperament, Childhood Trauma
Diagnostic methodClinically based on symptoms; Y-BOCS is the gold standard tool to assess severity
Differential diagnosisAnxiety disorder, major depressive disorder, eating disorders, tic disorders, obsessive–compulsive personality disorder
TreatmentCounseling, selective serotonin reuptake inhibitors, clomipramine
Frequency2.3%

Obsessive–compulsive disorder (OCD) is a mental and behavioral disorder in which an individual has intrusive thoughts (an obsession) and feels the need to perform certain routines (compulsions) repeatedly to relieve the distress caused by the obsession, to the extent where it impairs general function.

Obsessions are persistent unwanted thoughts, mental images, or urges that generate feelings of anxiety, disgust, or discomfort. Some common obsessions include fear of contamination, obsession with symmetry, the fear of acting blasphemously, the sufferer's sexual orientation, and the fear of possibly harming others or themselves. Compulsions are repeated actions or routines that occur in response to obsessions to achieve a relief from anxiety. Common compulsions include excessive hand washing, cleaning, counting, ordering, repeating, avoiding triggers, hoarding, neutralizing, seeking assurance, praying, and checking things. People with OCD may only perform mental compulsions such as needing to know or remember things. While this is sometimes referred to as primarily obsessional obsessive–compulsive disorder (Pure O), it is also considered a misnomer due to associated mental compulsions and reassurance seeking behaviors that are consistent with OCD.

Compulsions occur often and typically take up at least one hour per day, impairing one's quality of life. Compulsions cause relief in the moment, but cause obsessions to grow over time due to the repeated reward-seeking behavior of completing the ritual for relief. Many adults with OCD are aware that their compulsions do not make sense, but they still perform them to relieve the distress caused by obsessions. For this reason, thoughts and behaviors in OCD are usually considered egodystonic. In contrast, thoughts and behaviors in obsessive-compulsive personality disorder (OCPD) are usually considered egosyntonic, helping differentiate between the two.

Although the exact cause of OCD is unknown, several regions of the brain have been implicated in its neuroanatomical model including the anterior cingulate cortex, orbitofrontal cortex, amygdala, and BNST. The presence of a genetic component is evidenced by the increased likelihood for both identical twins to be affected than both fraternal twins. Risk factors include a history of child abuse or other stress-inducing events such as during the postpartum period or after streptococcal infections. Diagnosis is based on clinical presentation and requires ruling out other drug-related or medical causes; rating scales such as the Yale–Brown Obsessive–Compulsive Scale (Y-BOCS) assess severity. Other disorders with similar symptoms include generalized anxiety disorder, major depressive disorder, eating disorders, tic disorders, body-focused repetitive behavior, and obsessive–compulsive personality disorder. Personality disorders are a common comorbidity, with schizotypal and OCPD having poor treatment response. The condition is also associated with a general increase in suicidality. The phrase obsessive–compulsive is sometimes used in an informal manner unrelated to OCD to describe someone as excessively meticulous, perfectionistic, absorbed, or otherwise fixated. However, the actual disorder can vary in presentation, and individuals with OCD may not be concerned with cleanliness or symmetry.

OCD is chronic and long-lasting with periods of severe symptoms followed by periods of improvement. Treatment can improve ability to function and quality of life, and is usually reflected by improved Y-BOCS scores. Treatment for OCD may involve psychotherapy, pharmacotherapy such as antidepressants, or surgical procedures such as deep brain stimulation or, in extreme cases, psychosurgery. Psychotherapies derived from cognitive behavioral therapy (CBT) models, such as exposure and response prevention, acceptance and commitment therapy, and inference based-therapy, are more effective than non-CBT interventions. SSRIs are more effective when used in excess of the recommended depression dosage; however, higher doses can increase side effect intensity. Commonly used SSRIs include sertraline, fluoxetine, fluvoxamine, paroxetine, citalopram, and escitalopram. Some patients fail to improve after taking the maximum tolerated dose of multiple SSRIs for at least two months; these cases qualify as treatment-resistant and can require second-line treatment such as clomipramine or atypical antipsychotic augmentation. While SSRIs continue to be first-line, recent data for treatment-resistant OCD supports adjunctive use of neuroleptic medications, deep-brain stimulation, and neurosurgical ablation. There is growing evidence to support the use of deep brain stimulation and repetitive transcranial magnetic stimulation for treatment-resistant obsessive-compulsive disorder.

Obsessive–compulsive disorder affects about 2.3% of people at some point in their lives, while rates during any given year are about 1.2%. More than three million Americans suffer from OCD. According to Mercy, approximately 1 in 40 U.S. adults and 1 in 100 U.S. children have OCD. Although possible at times with triggers such as pregnancy, onset rarely occurs after age 35, and about 50% of patients experience detrimental effects to daily life before age 20. While OCD occurs worldwide, a recent meta-analysis showed that women are 1.6 times more likely to experience OCD. Based on data from 34 studies, the worldwide prevalence rate is 1.5% in women and 1% in men.

Signs and symptoms

OCD can present with a wide variety of symptoms. Certain groups of symptoms usually occur together as dimensions or clusters, which may reflect an underlying process. The standard assessment tool for OCD, the Yale–Brown Obsessive Compulsive Scale (Y-BOCS), has 13 predefined categories of symptoms. These symptoms fit into three to five groupings. A meta-analytic review of symptom structures found a four-factor grouping structure to be most reliable: symmetry factor, forbidden thoughts factor, cleaning factor, and hoarding factor. The symmetry factor correlates highly with obsessions related to ordering, counting, and symmetry, as well as repeating compulsions. The forbidden thoughts factor correlates highly with intrusive thoughts of a violent, religious, or sexual nature. The cleaning factor correlates highly with obsessions about contamination and compulsions related to cleaning. The hoarding factor only involves hoarding-related obsessions and compulsions, and was identified as being distinct from other symptom groupings.

When looking into the onset of OCD, one study suggests that there are differences in the age of onset between males and females, with the average age of onset of OCD being 9.6 for male children and 11.0 for female children. Children with OCD often have other mental disorders, such as ADHD, depression, anxiety, and disruptive behavior disorder. Continually, children are more likely to struggle in school and experience difficulties in social situations (Lack 2012). When looking at both adults and children a study found the average ages of onset to be 21 and 24 for males and females respectively. While some studies have shown that OCD with earlier onset is associated with greater severity, other studies have not been able to validate this finding. Looking at women specifically, a different study suggested that 62% of participants found that their symptoms worsened at a premenstrual age. Across the board, all demographics and studies showed a mean age of onset of less than 25.

Some OCD subtypes have been associated with improvement in performance on certain tasks, such as pattern recognition (washing subtype) and spatial working memory (obsessive thought subtype). Subgroups have also been distinguished by neuroimaging findings and treatment response, though neuroimaging studies have not been comprehensive enough to draw conclusions. Subtype-dependent treatment response has been studied, and the hoarding subtype has consistently been least responsive to treatment.

While OCD is considered a homogeneous disorder from a neuropsychological perspective, many of the symptoms may be the result of comorbid disorders. For example, adults with OCD have exhibited more symptoms of attention–deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) than adults without OCD.

In regards to the cause of onset, researchers asked participants in one study what they felt was responsible for triggering the initial onset of their illness. 29% of patients answered that there was an environmental factor in their life that did so. Specifically, the majority of participants who answered with that noted their environmental factor to be related to an increased responsibility.

Obsessions

People with OCD may face intrusive thoughts, such as thoughts about the devil (shown is a painted interpretation of Hell).

Obsessions are stress-inducing thoughts that recur and persist, despite efforts to ignore or confront them. People with OCD frequently perform tasks, or compulsions, to seek relief from obsession-related anxiety. Within and among individuals, initial obsessions vary in clarity and vividness. A relatively vague obsession could involve a general sense of disarray or tension, accompanied by a belief that life cannot proceed as normal while the imbalance remains. A more intense obsession could be a preoccupation with the thought or image of a close family member or friend dying, or intrusive thoughts related to relationship rightness. Other obsessions concern the possibility that someone or something other than oneself—such as God, the devil, or disease—will harm either the patient or the people or things the patient cares about. Others with OCD may experience the sensation of invisible protrusions emanating from their bodies, or feel that inanimate objects are ensouled. Another common obsession is scrupulosity, the pathological guilt/anxiety about moral or religious issues. In scrupulosity, a person's obsessions focus on moral or religious fears, such as the fear of being an evil person or the fear of divine retribution for sin. Mysophobia, a pathological fear of contamination and germs, is another common obsession theme.

Some people with OCD experience sexual obsessions that may involve intrusive thoughts or images of "kissing, touching, fondling, oral sex, anal sex, intercourse, incest, and rape" with "strangers, acquaintances, parents, children, family members, friends, coworkers, animals, and religious figures", and can include heterosexual or homosexual contact with people of any age. Similar to other intrusive thoughts or images, some disquieting sexual thoughts are normal at times, but people with OCD may attach extraordinary significance to such thoughts. For example, obsessive fears about sexual orientation can appear to the affected individual, and even to those around them, as a crisis of sexual identity. Furthermore, the doubt that accompanies OCD leads to uncertainty regarding whether one might act on the troubling thoughts, resulting in self-criticism or self-loathing.

Most people with OCD understand that their thoughts do not correspond with reality; however, they feel that they must act as though these ideas are correct or realistic. For example, someone who engages in compulsive hoarding might be inclined to treat inorganic matter as if it had the sentience or rights of living organisms, despite accepting that such behavior is irrational on an intellectual level. There is debate as to whether hoarding should be considered an independent syndrome from OCD.

Compulsions

A person exhibiting skin-picking disorder

Some people with OCD perform compulsive rituals because they inexplicably feel that they must do so, while others act compulsively to mitigate the anxiety that stems from obsessive thoughts. The affected individual might feel that these actions will either prevent a dreaded event from occurring, or push the event from their thoughts. In any case, their reasoning is so idiosyncratic or distorted that it results in significant distress, either personally, or for those around the affected individual. Excessive skin picking, hair pulling, nail biting, and other body-focused repetitive behavior disorders are all on the obsessive–compulsive spectrum. Some individuals with OCD are aware that their behaviors are not rational, but they feel compelled to follow through with them to fend off feelings of panic or dread. Furthermore, compulsions often stem from memory distrust, a symptom of OCD characterized by insecurity in one's skills in perception, attention, and memory, even in cases where there is no clear evidence of a deficit.

Common compulsions may include hand washing, cleaning, checking things (such as locks on doors), repeating actions (such as repeatedly turning on and off switches), ordering items in a certain way, and requesting reassurance. Although some individuals perform actions repeatedly, they do not necessarily perform these actions compulsively; for example, morning or nighttime routines and religious practices are not usually compulsions. Whether behaviors qualify as compulsions or mere habit depends on the context in which they are performed. For instance, arranging and ordering books for eight hours a day would be expected of someone who works in a library, but this routine would seem abnormal in other situations. In other words, habits tend to bring efficiency to one's life, while compulsions tend to disrupt it. Furthermore, compulsions are different from tics (such as touching, tapping, rubbing, or blinking) and stereotyped movements (such as head banging, body rocking, or self-biting), which are usually not as complex and not precipitated by obsessions. It can sometimes be difficult to tell the difference between compulsions and complex tics, and about 10–40% of people with OCD also have a lifetime tic disorder.

People with OCD rely on compulsions as an escape from their obsessive thoughts; however, they are aware that relief is only temporary, and that intrusive thoughts will return. Some affected individuals use compulsions to avoid situations that may trigger obsessions. Compulsions may be actions directly related to the obsession, such as someone obsessed with contamination compulsively washing their hands, but they can be unrelated as well. In addition to experiencing the anxiety and fear that typically accompanies OCD, affected individuals may spend hours performing compulsions every day. In such situations, it can become difficult for the person to fulfill their work, familial, or social roles. These behaviors can also cause adverse physical symptoms; for example, people who obsessively wash their hands with antibacterial soap and hot water can make their skin red and raw with dermatitis.

Individuals with OCD often use rationalizations to explain their behavior; however, these rationalizations do not apply to the behavioral pattern, but to each individual occurrence. For example, someone compulsively checking the front door may argue that the time and stress associated with one check is less than the time and stress associated with being robbed, and checking is consequently the better option. This reasoning often occurs in a cyclical manner, and can continue for as long as the affected person needs it to in order to feel safe.

In cognitive behavioral therapy (CBT), OCD patients are asked to overcome intrusive thoughts by not indulging in any compulsions. They are taught that rituals keep OCD strong, while not performing them causes OCD to become weaker. This position is supported by the pattern of memory distrust; the more often compulsions are repeated, the more weakened memory trust becomes, and this cycle continues as memory distrust increases compulsion frequency. For body-focused repetitive behaviors (BFRB) such as trichotillomania (hair pulling), skin picking, and onychophagia (nail biting), behavioral interventions such as habit reversal training and decoupling are recommended for the treatment of compulsive behaviors.

OCD sometimes manifests without overt compulsions, which may be termed "primarily obsessional OCD." OCD without overt compulsions could, by one estimate, characterize as many as 50–60% of OCD cases.

Insight and overvalued ideation

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5), identifies a continuum for the level of insight in OCD, ranging from good insight (the least severe) to no insight (the most severe). Good or fair insight is characterized by the acknowledgment that obsessive–compulsive beliefs are not or may not be true, while poor insight, in the middle of the continuum, is characterized by the belief that obsessive–compulsive beliefs are probably true. The absence of insight altogether, in which the individual is completely convinced that their beliefs are true, is also identified as a delusional thought pattern, and occurs in about 4% of people with OCD. When cases of OCD with no insight become severe, affected individuals have an unshakable belief in the reality of their delusions, which can make their cases difficult to differentiate from psychotic disorders.

Some people with OCD exhibit what is known as overvalued ideas, ideas that are abnormal compared to affected individuals' respective cultures, and more treatment-resistant than most negative thoughts and obsessions. After some discussion, it is possible to convince the individual that their fears are unfounded. It may be more difficult to practice exposure and response prevention therapy (ERP) on such people, as they may be unwilling to cooperate, at least initially. Similar to how insight is identified on a continuum, obsessive-compulsive beliefs are characterized on a spectrum, ranging from obsessive doubt to delusional conviction. In the United States, overvalued ideation (OVI) is considered most akin to poor insight—especially when considering belief strength as one of an idea's key identifiers. Furthermore, severe and frequent overvalued ideas are considered similar to idealized values, which are so rigidly held by, and so important to affected individuals, that they end up becoming a defining identity. In adolescent OCD patients, OVI is considered a severe symptom.

Historically, OVI has been thought to be linked to poorer treatment outcome in patients with OCD, but it is currently considered a poor indicator of prognosis. The Overvalued Ideas Scale (OVIS) has been developed as a reliable quantitative method of measuring levels of OVI in patients with OCD, and research has suggested that overvalued ideas are more stable for those with more extreme OVIS scores.

Cognitive performance

Though OCD was once believed to be associated with above-average intelligence, this does not appear to necessarily be the case. A 2013 review reported that people with OCD may sometimes have mild but wide-ranging cognitive deficits, most significantly those affecting spatial memory and to a lesser extent with verbal memory, fluency, executive function, and processing speed, while auditory attention was not significantly affected. People with OCD show impairment in formulating an organizational strategy for coding information, set-shifting, and motor and cognitive inhibition.

Specific subtypes of symptom dimensions in OCD have been associated with specific cognitive deficits. For example, the results of one meta-analysis comparing washing and checking symptoms reported that washers outperformed checkers on eight out of ten cognitive tests. The symptom dimension of contamination and cleaning may be associated with higher scores on tests of inhibition and verbal memory.

Video game addiction

Pediatric OCD

Approximately 1–2% of children are affected by OCD. There is a lot of similarity between the clinical presentation of OCD in children and adults, and it is considered a highly familial disorder, with a phenotypic heritability of around 50%. Obsessive–compulsive disorder symptoms tend to develop more frequently in children 10–14 years of age, with males displaying symptoms at an earlier age, and at a more severe level than females. In children, symptoms can be grouped into at least four types, including sporadic and tic-related OCD.

The Children's Yale–Brown Obsessive–Compulsive Scale (CY-BOCS) is the gold standard measure for assessment of pediatric OCD. It follows the Y-BOCS format, but with a Symptom Checklist that is adapted for developmental appropriateness. Insight, avoidance, indecisiveness, responsibility, pervasive slowness, and doubting, are not included in a rating of overall severity. The CY-BOCS has demonstrated good convergent validity with clinician-rated OCD severity, and good to fair discriminant validity from measures of closely related anxiety, depression, and tic severity. The CY-BOCS Total Severity score is an important monitoring tool as it is responsive to pharmacotherapy and psychotherapy. Positive treatment response is characterized by 25% reduction in CY-BOCS total score, and diagnostic remission is associated with a 45%-50% reduction in Total Severity score (or a score <15).

CBT is the first line treatment for mild to moderate cases of OCD in children, while medication plus CBT is recommended for moderate to severe cases. Serotonin reuptake inhibitors (SRIs) are first-line medications for OCD in children with established AACAP guidelines for dosing.

Associated conditions

People with OCD may be diagnosed with other conditions as well, such as obsessive–compulsive personality disorder, major depressive disorder, bipolar disorder, generalized anxiety disorder, anorexia nervosa, social anxiety disorder, bulimia nervosa, Tourette syndrome, transformation obsession, ASD, ADHD, dermatillomania, body dysmorphic disorder, and trichotillomania. More than 50% of people with OCD experience suicidal tendencies, and 15% have attempted suicide. Depression, anxiety, and prior suicide attempts increase the risk of future suicide attempts.

It has been found that between 18 and 34% of females currently experiencing OCD scored positively on an inventory measuring disordered eating. Another study found that 7% are likely to have an eating disorder, while another found that fewer than 5% of males have OCD and an eating disorder.

Individuals with OCD have also been found to be affected by delayed sleep phase disorder at a substantially higher rate than the general public. Moreover, severe OCD symptoms are consistently associated with greater sleep disturbance. Reduced total sleep time and sleep efficiency have been observed in people with OCD, with delayed sleep onset and offset.

Some research has demonstrated a link between drug addiction and OCD. For example, there is a higher risk of drug addiction among those with any anxiety disorder, likely as a way of coping with the heightened levels of anxiety. However, drug addiction among people with OCD may be a compulsive behavior. Depression is also extremely prevalent among people with OCD. One explanation for the high depression rate among OCD populations was posited by Mineka, Watson, and Clark (1998), who explained that people with OCD, or any other anxiety disorder, may feel "out of control".

Someone exhibiting OCD signs does not necessarily have OCD. Behaviors that present as obsessive–compulsive can also be found in a number of other conditions, including obsessive–compulsive personality disorder (OCPD), autism spectrum disorder (ASD), or disorders in which perseveration is a possible feature (ADHD, PTSD, bodily disorders, or stereotyped behaviors). Some cases of OCD present symptoms typically associated with Tourette syndrome, such as compulsions that may appear to resemble motor tics; this has been termed tic-related OCD or Tourettic OCD.

OCD frequently occurs comorbidly with both bipolar disorder and major depressive disorder. Between 60 and 80% of those with OCD experience a major depressive episode in their lifetime. Comorbidity rates have been reported at between 19 and 90%, as a result of methodological differences. Between 9–35% of those with bipolar disorder also have OCD, compared to 1–2% in the general population. About 50% of those with OCD experience cyclothymic traits or hypomanic episodes. OCD is also associated with anxiety disorders. Lifetime comorbidity for OCD has been reported at 22% for specific phobia, 18% for social anxiety disorder, 12% for panic disorder, and 30% for generalized anxiety disorder. The comorbidity rate for OCD and ADHD has been reported to be as high as 51%.

Causes

The cause of OCD is unknown. Both environmental and genetic factors are believed to play a role. Risk factors include a history of adverse childhood experiences or other stress-inducing events.

Drug-induced OCD

Some medications, toxin exposures, and drugs, such as methamphetamine or cocaine, can induce obsessive-compulsive disorder (OCD) in people without previous symptoms. Some atypical antipsychotics (second-generation antipsychotics) such as olanzapine (Zyprexa) and clozapine (Clozaril) can induce OCD in people, particularly individuals with schizophrenia.

The diagnostic criteria include:

1) General OCD symptoms (obsessions, compulsions, skin picking, hair pulling, etc.) that developed soon after exposure to the substance or medication which can produce such symptoms.

2) The onset of symptoms cannot be explained by an obsessive-compulsive and related disorder that is not substance/medication-induced and should last for a substantial period of time (about 1 month)

3) This disturbance does not only occur during delirium.

4) Clinically induces distress or impairment in social, occupational, or other important areas of functioning. 

Genetics

There appear to be some genetic components of OCD causation, with identical twins more often affected than fraternal twins. Furthermore, individuals with OCD are more likely to have first-degree family members exhibiting the same disorders than matched controls. In cases in which OCD develops during childhood, there is a much stronger familial link in the disorder than with cases in which OCD develops later in adulthood. In general, genetic factors account for 45–65% of the variability in OCD symptoms in children diagnosed with the disorder. A 2007 study found evidence supporting the possibility of a heritable risk for OCD.

Research has found there to be a genetic correlation between anorexia nervosa and OCD, suggesting a strong etiology. First and second hand relatives of probands with OCD have a greater risk of developing anorexia nervosa as genetic relatedness increases.

A mutation has been found in the human serotonin transporter gene hSERT in unrelated families with OCD.

A systematic review found that while neither allele was associated with OCD overall, in Caucasians, the L allele was associated with OCD. Another meta-analysis observed an increased risk in those with the homozygous S allele, but found the LS genotype to be inversely associated with OCD.

A genome-wide association study found OCD to be linked with single-nucleotide polymorphisms (SNPs) near BTBD3, and two SNPs in DLGAP1 in a trio-based analysis, but no SNP reached significance when analyzed with case-control data.

One meta-analysis found a small but significant association between a polymorphism in SLC1A1 and OCD.

The relationship between OCD and Catechol-O-methyltransferase (COMT) has been inconsistent, with one meta-analysis reporting a significant association, albeit only in men, and another meta analysis reporting no association.

It has been postulated by evolutionary psychologists that moderate versions of compulsive behavior may have had evolutionary advantages. Examples would be moderate constant checking of hygiene, the hearth, or the environment for enemies. Similarly, hoarding may have had evolutionary advantages. In this view, OCD may be the extreme statistical tail of such behaviors, possibly the result of a high number of predisposing genes.

Brain structure and functioning

Imaging studies have shown differences in the frontal cortex and subcortical structures of the brain in patients with OCD. There appears to be a connection between the OCD symptoms and abnormalities in certain areas of the brain, but such a connection is not clear. Some people with OCD have areas of unusually high activity in their brain, or low levels of the chemical serotonin, which is a neurotransmitter that some nerve cells use to communicate with each other, and is thought to be involved in regulating many functions, influencing emotions, mood, memory, and sleep.

Autoimmune

A controversial hypothesis is that some cases of rapid onset of OCD in children and adolescents may be caused by a syndrome connected to Group A streptococcal infections (GABHS), known as pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). OCD and tic disorders are hypothesized to arise in a subset of children as a result of a post-streptococcal autoimmune process. The PANDAS hypothesis is unconfirmed and unsupported by data, and two new categories have been proposed: PANS (pediatric acute-onset neuropsychiatric syndrome) and CANS (childhood acute neuropsychiatric syndrome). The CANS and PANS hypotheses include different possible mechanisms underlying acute-onset neuropsychiatric conditions, but do not exclude GABHS infections as a cause in a subset of individuals. PANDAS, PANS, and CANS are the focus of clinical and laboratory research, but remain unproven. Whether PANDAS is a distinct entity differing from other cases of tic disorders or OCD is debated.

A review of studies examining anti-basal ganglia antibodies in OCD found an increased risk of having anti-basal ganglia antibodies in those with OCD versus the general population.

Environment

OCD may be more common in people who have been bullied, abused, or neglected, and it sometimes starts after a significant life event, such as childbirth or bereavement. It has been reported in some studies that there is a connection between childhood trauma and obsessive-compulsive symptoms. More research is needed to understand this relationship better.

Mechanisms

Neuroimaging

Some parts of the brain showing abnormal activity in OCD: Orbitofrontal cortex integrates rewards, emotions, and behaviors; anterior cingulate cortex is involved in error detection; amygdala is involved in emotional interpretation of reward

Functional neuroimaging during symptom provocation has observed abnormal activity in the orbitofrontal cortex (OFC), left dorsolateral prefrontal cortex (dlPFC), right premotor cortex, left superior temporal gyrus, globus pallidus externus, hippocampus, and right uncus. Weaker foci of abnormal activity were found in the left caudate, posterior cingulate cortex, and superior parietal lobule. However, an older meta-analysis of functional neuroimaging in OCD reported that the only consistent functional neuroimaging finding was increased activity in the orbital gyrus and head of the caudate nucleus, while anterior cingulate cortex (ACC) activation abnormalities were too inconsistent.

A meta-analysis comparing affective and nonaffective tasks observed differences with controls in regions implicated in salience, habit, goal-directed behavior, self-referential thinking, and cognitive control. For nonaffective tasks, hyperactivity was observed in the insula, ACC, and head of the caudate/putamen, while hypoactivity was observed in the medial prefrontal cortex (mPFC) and posterior caudate. Affective tasks were observed to relate to increased activation in the precuneus and posterior cingulate cortex, while decreased activation was found in the pallidum, ventral anterior thalamus, and posterior caudate. The involvement of the cortico-striato-thalamo-cortical loop in OCD, as well as the high rates of comorbidity between OCD and ADHD, have led some to draw a link in their mechanism. Observed similarities include dysfunction of the anterior cingulate cortex and prefrontal cortex, as well as shared deficits in executive functions. The involvement of the orbitofrontal cortex and dorsolateral prefrontal cortex in OCD is shared with bipolar disorder, and may explain the high degree of comorbidity. Decreased volumes of the dorsolateral prefrontal cortex related to executive function has also been observed in OCD.

People with OCD evince increased grey matter volumes in bilateral lenticular nuclei, extending to the caudate nuclei, with decreased grey matter volumes in bilateral dorsal medial frontal/anterior cingulate gyri. These findings contrast with those in people with other anxiety disorders, who evince decreased (rather than increased) grey matter volumes in bilateral lenticular/caudate nuclei, as well as decreased grey matter volumes in bilateral dorsal medial frontal/anterior cingulate gyri. Increased white matter volume and decreased fractional anisotropy in anterior midline tracts has been observed in OCD, possibly indicating increased fiber crossings.

Cognitive models

Generally, two categories of models for OCD have been postulated. The first category involves deficits in executive dysfunction and is based on the observed structural and functional abnormalities in the dlPFC, striatum and thalamus. The second category involves dysfunctional modulatory control and primarily relies on observed functional and structural differences in the ACC, mPFC, and OFC.

One proposed model suggests that dysfunction in the OFC leads to improper valuation of behaviors and decreased behavioral control, while the observed alterations in amygdala activations leads to exaggerated fears and representations of negative stimuli.

Due to the heterogeneity of OCD symptoms, studies differentiating various symptoms have been performed. Symptom-specific neuroimaging abnormalities include the hyperactivity of caudate and ACC in checking rituals, while finding increased activity of cortical and cerebellar regions in contamination-related symptoms. Neuroimaging differentiating content of intrusive thoughts has found differences between aggressive as opposed to taboo thoughts, finding increased connectivity of the amygdala, ventral striatum, and ventromedial prefrontal cortex in aggressive symptoms, while observing increased connectivity between the ventral striatum and insula in sexual or religious intrusive thoughts.

Another model proposes that affective dysregulation links excessive reliance on habit-based action selection with compulsions. This is supported by the observation that those with OCD demonstrate decreased activation of the ventral striatum when anticipating monetary reward, as well as increased functional connectivity between the VS and the OFC. Furthermore, those with OCD demonstrate reduced performance in Pavlovian fear-extinction tasks, hyperresponsiveness in the amygdala to fearful stimuli, and hyporesponsiveness in the amygdala when exposed to positively valanced stimuli. Stimulation of the nucleus accumbens has also been observed to effectively alleviate both obsessions and compulsions, supporting the role of affective dysregulation in generating both.

Neurobiological

From the observation of the efficacy of antidepressants in OCD, a serotonin hypothesis of OCD has been formulated. Studies of peripheral markers of serotonin, as well as challenges with proserotonergic compounds have yielded inconsistent results, including evidence pointing towards basal hyperactivity of serotonergic systems. Serotonin receptor and transporter binding studies have yielded conflicting results, including higher and lower serotonin receptor 5-HT2A and serotonin transporter binding potentials that were normalized by treatment with SSRIs. Despite inconsistencies in the types of abnormalities found, evidence points towards dysfunction of serotonergic systems in OCD. Orbitofrontal cortex overactivity is attenuated in people who have successfully responded to SSRI medication, a result believed to be caused by increased stimulation of serotonin receptors 5-HT2A and 5-HT2C.

A complex relationship between dopamine and OCD has been observed. Although antipsychotics, which act by antagonizing dopamine receptors, may improve some cases of OCD, they frequently exacerbate others. Antipsychotics, in the low doses used to treat OCD, may actually increase the release of dopamine in the prefrontal cortex, through inhibiting autoreceptors. Further complicating things is the efficacy of amphetamines, decreased dopamine transporter activity observed in OCD, and low levels of D2 binding in the striatum. Furthermore, increased dopamine release in the nucleus accumbens after deep brain stimulation correlates with improvement in symptoms, pointing to reduced dopamine release in the striatum playing a role in generating symptoms.

Abnormalities in glutamatergic neurotransmission have been implicated in OCD. Findings such as increased cerebrospinal glutamate, less consistent abnormalities observed in neuroimaging studies, and the efficacy of some glutamatergic drugs (such as the glutamate-inhibiting riluzole) have implicated glutamate in OCD. OCD has been associated with reduced N-Acetylaspartic acid in the mPFC, which is thought to reflect neuron density or functionality, although the exact interpretation has not been established.

Diagnosis

Formal diagnosis may be performed by a psychologist, psychiatrist, clinical social worker, or other licensed mental health professional. OCD, like other mental and behavioral health disorders, cannot be diagnosed by a medical exam, nor are there any medical exams that can predict if one will fall victim to such illnesses. To be diagnosed with OCD, a person must have obsessions, compulsions, or both, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM). The DSM notes that there are multiple characteristics that can turn obsessions and compulsions from normalized behavior to "clinically significant". There has to be recurring and strong thoughts or impulsive that intrude on the day-to-day lives of the patients and cause noticeable levels of anxiousness.

These thoughts, impulses, or images are of a degree or type that lies outside the normal range of worries about conventional problems. A person may attempt to ignore or suppress such obsessions, neutralize them with another thought or action, or try to rationalize their anxiety away. People with OCD tend to recognize their obsessions as irrational.

Compulsions become clinically significant when a person feels driven to perform them in response to an obsession, or according to rules that must be applied rigidly, and when the person consequently feels or causes significant distress. Therefore, while many people who do not have OCD may perform actions often associated with OCD (such as ordering items in a pantry by height), the distinction with clinically significant OCD lies in the fact that the person with OCD must perform these actions to avoid significant psychological distress. These behaviors or mental acts are aimed at preventing or reducing distress or preventing some dreaded event or situation; however, these activities are not logically or practically connected to the issue, or, they are excessive.

Moreover, the obsessions or compulsions must be time-consuming, often taking up more than one hour per day, or cause impairment in social, occupational, or scholastic functioning. It is helpful to quantify the severity of symptoms and impairment before and during treatment for OCD. In addition to the person's estimate of the time spent each day harboring obsessive-compulsive thoughts or behaviors, concrete tools can be used to gauge the person's condition. This may be done with rating scales, such as the Yale–Brown Obsessive Compulsive Scale (Y-BOCS; expert rating) or the obsessive-compulsive inventory (OCI-R; self-rating). With measurements such as these, psychiatric consultation can be more appropriately determined, as it has been standardized.

In regards to diagnosing, the health professional also looks to make sure that the signs of obsessions and compulsions are not the results of any drugs, prescription or recreational, that the patient may be taking.

There are several types of obsessive thoughts that are found commonly in those with OCD. Some of these include fear of germs, hurting loved ones, embarrassment, neatness, societally unacceptable sexual thoughts etc. Within OCD, these specific categories are often diagnosed into their own type of OCD.

OCD is sometimes placed in a group of disorders called the obsessive–compulsive spectrum.

Another criterion in the DSM is that a person's mental illness does not fit one of the other categories of a mental disorder better. That is to say, if the obsessions and compulsions of a patient could be better described by trichotillomania, it would not be diagnosed as OCD. That being said, OCD does often go hand in hand with other mental disorders. For this reason, one may be diagnosed with multiple mental disorders at once.

A different aspect of the diagnoses is the degree of insight had by the individual in regards to the truth of the obsessions. There are three levels, good/fair, poor and absent/delusional. Good/fair indicated that the patient is aware that the obsessions they have are not true or probably not true. Poor indicates that the patient believes their obsessional beliefs are probably true. Absent/delusional indicates that they fully believe their obsessional thoughts to be true. Approximately 4% or fewer individuals with OCD will be diagnosed as absent/delusional. Additionally, as many as 30% of those with OCD also have a lifetime tic disorder, meaning they have been diagnosed with a tic disorder at some point in their life.

There are several different types of tics that have been observed in individuals with OCD. These include but are not limited to, "grunting", "jerking" or "shrugging" body parts, sniffling, and excessive blinking.

There has been a significant amount of progress over the last few decades, and as of 2022 there is statically significant improvement in the diagnostic process for individuals with OCD. One study found that of two groups of individuals, one with participants under the age of 27.25 and one with participants over that age, those in the younger group experienced a significantly faster time between the onset of OCD tendencies and their formal diagnoses.

Differential diagnosis

OCD is often confused with the separate condition obsessive–compulsive personality disorder (OCPD). OCD is egodystonic, meaning that the disorder is incompatible with the individual's self-concept. As egodystonic disorders go against a person's self-concept, they tend to cause much distress. OCPD, on the other hand, is egosyntonic, marked by the person's acceptance that the characteristics and behaviors displayed as a result are compatible with their self-image, or are otherwise appropriate, correct, or reasonable.

As a result, people with OCD are often aware that their behavior is not rational, and are unhappy about their obsessions, but nevertheless feel compelled by them. By contrast, people with OCPD are not aware of anything abnormal; they will readily explain why their actions are rational. It is usually impossible to convince them otherwise, and they tend to derive pleasure from their obsessions or compulsions.

Management

Cognitive behavioral therapy (CBT) and psychotropic medications are the first-line treatments for OCD.

Therapy

One exposure and ritual prevention activity would be to check the lock only once and then leave.

One specific CBT technique used is called exposure and response prevention (ERP), which involves teaching the person to deliberately come into contact with situations that trigger obsessive thoughts and fears (exposure), without carrying out the usual compulsive acts associated with the obsession (response prevention). This technique causes patients to gradually learn to tolerate the discomfort and anxiety associated with not performing their compulsions. For many patients, ERP is the add-on treatment of choice when selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs) medication does not effectively treat OCD symptoms, or vice versa, for individuals who begin treatment with psychotherapy. This technique is considered superior to others due to the lack of medication used. However, up to 25% of patients will discontinue treatment due to the severity of their tics. CBT normally lasts anywhere from 12-16 sessions, with homework assigned to the patient in between meetings with a therapist. (Lack 2012). Modalities differ in ERP treatment but both virtual reality based as well as unguided computer assisted treatment programs have shown effective results in treatment programs.

For example, a patient might be asked to touch something very mildly contaminated (exposure), and wash their hands only once afterward (response prevention). Another example might entail asking the patient to leave the house and check the lock only once (exposure), without going back to check again (response prevention). After succeeding at one stage of treatment, the patient's level of discomfort in the exposure phase can be increased. When this therapy is successful, the patient will quickly habituate to an anxiety-producing situation, discovering a considerable drop in anxiety level.

ERP has a strong evidence base, and is considered the most effective treatment for OCD. However, this claim was doubted by some researchers in 2000, who criticized the quality of many studies. While ERP can lead a majority of clients to improvements, many do not reach remission or become asymptomatic; some therapists are also hesitant to use this approach.

The recent development of remotely technology-delivered CBT is increasing access to therapy options for those living with OCD and remote versions appear to equally as effective as in-person therapy options. The development of smartphone interventions for OCD that utilize CBT techniques are another alternative that is expanding access to therapy while allowing therapies to be personalized for each patient.

Acceptance and commitment therapy (ACT), a newer therapy also used to treat anxiety and depression, has also been found to be effective in treatment of OCD. ACT uses acceptance and mindfulness strategies to teach patients not to overreact to or avoid unpleasant thoughts and feelings but rather "move toward valued behavior."

Inference-based therapy (IBT) is a form of cognitive therapy specifically developed for treating OCD. The therapy posits that individuals with OCD put a greater emphasis on an imagined possibility than on what can be perceived with the senses, and confuse the imagined possibility with reality, in a process called inferential confusion. According to inference-based therapy, obsessional thinking occurs when the person replaces reality and real probabilities with imagined possibilities. The goal of inference-based therapy is to reorient clients towards trusting the senses and relating to reality in a normal, non-effortful way. Differences between normal and obsessional doubts are presented, and clients are encouraged to use their senses and reasoning as they do in non-obsessive-compulsive disorder situations. Research on Inference-Based Cognitive-Behavior Therapy (I-CBT) suggests it can lead to improvements for those with OCD.

A 2007 Cochrane review found that psychological interventions derived from CBT models, such as ERP, ACT, and IBT, were more effective than non-CBT interventions. Other forms of psychotherapy, such as psychodynamics and psychoanalysis, may help in managing some aspects of the disorder. However, in 2007, the American Psychiatric Association (APA) noted a lack of controlled studies showing their efficacy, "in dealing with the core symptoms of OCD." For body-focused repetitive behaviors (BFRB), behavioral interventions such as habit-reversal training and decoupling are recommended.

Psychotherapy in combination with psychiatric medication may be more effective than either option alone for individuals with severe OCD. ERP coupled with weight restoration and serotonin reuptake inhibitors has proven the most effective when treating OCD and an eating disorder simultaneously.

Medication

A blister pack of sertraline under the brand name Zoloft

The medications most frequently used to treat OCD are antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). Sertraline and fluoxetine are effective in treating OCD for children and adolescents.

SSRIs help people with OCD by inhibiting the reabsorption of serotonin by the nerve cells after they carry messages from neurons to synapse; thus, more serotonin is available to pass further messages between nearby nerve cells.

SSRIs are a second-line treatment of adult OCD with mild functional impairment, and as first-line treatment for those with moderate or severe impairment. In children, SSRIs can be considered as a second-line therapy in those with moderate to severe impairment, with close monitoring for psychiatric adverse effects. Patients treated with SSRIs are about twice as likely to respond to treatment as are those treated with placebo, so this treatment is qualified as efficacious. Efficacy has been demonstrated both in short-term (6–24 weeks) treatment trials, and in discontinuation trials with durations of 28–52 weeks.

Clomipramine, a medication belonging to the class of tricyclic antidepressants, appears to work as well as SSRIs, but has a higher rate of side effects.

In 2006, the National Institute for Health and Care Excellence (NICE) guidelines recommended augmentative second-generation (atypical) antipsychotics for treatment-resistant OCD. Atypical antipsychotics are not useful when used alone, and no evidence supports the use of first-generation antipsychotics. For OCD treatment specifically, there is tentative evidence for risperidone, and insufficient evidence for olanzapine. Quetiapine is no better than placebo with regard to primary outcomes, but small effects were found in terms of Y-BOCS score. The efficacy of quetiapine and olanzapine are limited by an insufficient number of studies. A 2014 review article found two studies that indicated that aripiprazole was "effective in the short-term", and found that "[t]here was a small effect-size for risperidone or anti-psychotics in general in the short-term"; however, the study authors found "no evidence for the effectiveness of quetiapine or olanzapine in comparison to placebo." While quetiapine may be useful when used in addition to an SSRI/SNRI in treatment-resistant OCD, these drugs are often poorly tolerated, and have metabolic side effects that limit their use. A guideline by the American Psychological Association suggested that dextroamphetamine may be considered by itself after more well-supported treatments have been attempted.

Procedures

Electroconvulsive therapy (ECT) has been found to have effectiveness in some severe and refractory cases. Transcranial magnetic stimulation has shown to provide therapeutic benefits in alleviating symptoms.

Surgery may be used as a last resort in people who do not improve with other treatments. In this procedure, a surgical lesion is made in an area of the brain (the cingulate cortex). In one study, 30% of participants benefitted significantly from this procedure. Deep brain stimulation and vagus nerve stimulation are possible surgical options that do not require destruction of brain tissue. However, because deep brain stimulation results in such an instant and intense change, individuals may experience identity challenges afterward. In the United States, the Food and Drug Administration approved deep-brain stimulation for the treatment of OCD under a humanitarian device exemption, requiring that the procedure be performed only in a hospital with special qualifications to do so.

In the United States, psychosurgery for OCD is a treatment of last resort, and will not be performed until the person has failed several attempts at medication (at the full dosage) with augmentation, and many months of intensive cognitive–behavioral therapy with exposure and ritual/response prevention. Likewise, in the United Kingdom, psychosurgery cannot be performed unless a course of treatment from a suitably qualified cognitive–behavioral therapist has been carried out.

Children

Therapeutic treatment may be effective in reducing ritual behaviors of OCD for children and adolescents. Similar to the treatment of adults with OCD, cognitive behavioral therapy stands as an effective and validated first line of treatment of OCD in children. Family involvement, in the form of behavioral observations and reports, is a key component to the success of such treatments. Parental interventions also provide positive reinforcement for a child who exhibits appropriate behaviors as alternatives to compulsive responses. In a recent meta-analysis of evidenced-based treatment of OCD in children, family-focused individual CBT was labeled as "probably efficacious," establishing it as one of the leading psychosocial treatments for youth with OCD. After one or two years of therapy, in which a child learns the nature of their obsession and acquires strategies for coping, they may acquire a larger circle of friends, exhibit less shyness, and become less self-critical. Trials have shown that children and adolescents with OCD should begin treatment with the combination of CBT with a selective serotonin reuptake inhibitor or CBT alone, rather than only an SSRI.

Although the known causes of OCD in younger age groups range from brain abnormalities to psychological preoccupations, life stress such as bullying and traumatic familial deaths may also contribute to childhood cases of OCD, and acknowledging these stressors can play a role in treating the disorder.

Prognosis

Quality of life is reduced across all domains in OCD. While psychological or pharmacological treatment can lead to a reduction of OCD symptoms and an increase in reported quality of life, symptoms may persist at moderate levels even following adequate treatment courses, and completely symptom-free periods are uncommon. In pediatric OCD, around 40% still have the disorder in adulthood, and around 40% qualify for remission. The risk of having at least one comorbid personality disorder in OCD is 52%, which is the highest among anxiety disorders and greatly impacts its management and prognosis.

Epidemiology

Age-standardized disability-adjusted life year estimated rates for obsessive-compulsive disorder per 100,000 inhabitants in 2004
  no data
  <45
  45–52.5
  52.5–60
  60–67.5
  67.5–75
  75–82.5
  82.5–90
  90–97.5
  97.5–105
  105–112.5
  112.5–120
  >120

Obsessive–compulsive disorder affects about 2.3% of people at some point in their life, with the yearly rate about 1.2%. OCD occurs worldwide. It is unusual for symptoms to begin after the age of 35 and half of people develop problems before 20. Males and females are affected about equally. However, there is an earlier age for onset for males than females.

History

Plutarch, an ancient Greek philosopher and historian, describes an ancient Roman man who possibly had scrupulosity, which could be a symptom of OCD or OCPD. This man is described as "turning pale under his crown of flowers," praying with a "faltering voice," and scattering "incense with trembling hands."

In the 7th century AD, John Climacus records an instance of a young monk plagued by constant and overwhelming "temptations to blasphemy" consulting an older monk, who told him: "My son, I take upon myself all the sins which these temptations have led you, or may lead you, to commit. All I require of you is that for the future you pay no attention to them whatsoever." The Cloud of Unknowing, a Christian mystical text from the late 14th century, recommends dealing with recurring obsessions by attempting to ignore them, and, if that fails, to "cower under them like a poor wretch and a coward overcome in battle, and reckon it to be a waste of your time for you to strive any longer against them", a technique now known as emotional flooding.

Abu Zayd Al-Balkhi, the 9th century Islamic polymath, was likely the first to classify OCD into different types and pioneer cognitive behavioral therapy, in a fashion unique to his era and which was not popular in Greek medicine. In his medical treatise entitled Sustenance of the Body and Soul, Al-Balkhi describes obsessions particular to the disorder as "Annoying thoughts that are not real. These intrusive thoughts prevent enjoying life, and performing daily activities. They affect concentration and interfere with ability to carry out different tasks." As treatment, Al-Balkhi suggests treating obsessive thoughts with positive thoughts and mind-based therapy.

From the 14th to the 16th century in Europe, it was believed that people who experienced blasphemous, sexual or other obsessive thoughts were possessed by the devil. Based on this reasoning, treatment involved banishing the "evil" from the "possessed" person through exorcism. The vast majority of people who thought that they were possessed by the devil did not have hallucinations or other "spectacular symptoms" but "complained of anxiety, religious fears, and evil thoughts." In 1584, a woman from Kent, England, named Mrs. Davie, described by a justice of the peace as "a good wife", was nearly burned at the stake after she confessed that she experienced constant, unwanted urges to murder her family.

The English term obsessive–compulsive arose as a translation of German Zwangsvorstellung (obsession) used in the first conceptions of OCD by Karl Westphal. Westphal's description went on to influence Pierre Janet, who further documented features of OCD. In the early 1910s, Sigmund Freud attributed obsessive–compulsive behavior to unconscious conflicts that manifest as symptoms. Freud describes the clinical history of a typical case of "touching phobia" as starting in early childhood, when the person has a strong desire to touch an item. In response, the person develops an "external prohibition" against this type of touching. However, this "prohibition does not succeed in abolishing" the desire to touch; all it can do is repress the desire and "force it into the unconscious." Freudian psychoanalysis remained the dominant treatment for OCD until the mid-1980s, even though medicinal and therapeutic treatments were known and available, because it was widely thought that these treatments would be detrimental to the effectiveness of the psychotherapy. In the mid-1980s, this approach changed, and practitioners began treating OCD primarily with medicine and practical therapy rather than through psychoanalysis.

One of the first successful treatments of OCD, exposure and response prevention, emerged during the 1960s, when psychologist Vic Meyer exposed two hospitalized patients to anxiety-inducing situations while preventing them from performing any compulsions. Eventually, both patients' anxiety level dropped to manageable levels. Meyer devised this procedure from his analysis of fear extinguishment in animals via flooding. The success of ERP clinically and scientifically has been summarized as "spectacular" by prominent OCD researcher Stanley Rachman decades following Meyer's creation of the method.

In 1967, psychiatrist Juan José López-Ibor reported that the drug clomipramine was effective in treating OCD. Many reports of its success in treatment followed, and several studies had confirmed its effectiveness by the 1980s. However, clomipramine was subsequently displaced by new SSRIs developed in the 1970s, such as fluoxetine and sertraline, which were shown to have less side effects.

Obsessive-compulsive symptoms worsened during the early stages of the COVID-19 pandemic, particularly for individuals with contamination-related OCD.

Notable cases

John Bunyan (1628–1688), the author of The Pilgrim's Progress, displayed symptoms of OCD (which had not yet been named). During the most severe period of his condition, he would mutter the same phrase over and over again to himself while rocking back and forth. He later described his obsessions in his autobiography Grace Abounding to the Chief of Sinners, stating, "These things may seem ridiculous to others, even as ridiculous as they were in themselves, but to me they were the most tormenting cogitations." He wrote two pamphlets advising those with similar anxieties. In one of them, he warns against indulging in compulsions: "Have care of putting off your trouble of spirit in the wrong way: by promising to reform yourself and lead a new life, by your performances or duties".

British poet, essayist and lexicographer Samuel Johnson (1709–1784) also had OCD. He had elaborate rituals for crossing the thresholds of doorways, and repeatedly walked up and down staircases counting the steps. He would touch every post on the street as he walked past, only step in the middle of paving stones, and repeatedly perform tasks as though they had not been done properly the first time.

The "Rat Man", real name Ernst Lanzer, a notable patient of Sigmund Freud, suffered from what was then called "obsessional neurosis". Lanzer's illness was characterised most famously by a pattern of distressing intrusive thoughts in which he feared that his father or a female friend would be subjected to a purported Chinese method of torture in which rats would be encouraged to gnaw their way out of a victim's body by a hot poker.

American aviator and filmmaker Howard Hughes is known to have had OCD, primarily an obsessive fear of germs and contamination. Friends of Hughes have also mentioned his obsession with minor flaws in clothing. This was conveyed in The Aviator (2004), a film biography of Hughes.

English singer-songwriter George Ezra has openly spoken about his life-long struggle with OCD, particularly primarily obsessional obsessive–compulsive disorder (Pure O).

World renowned Swedish climate activist Greta Thunberg is also known to have OCD, among other mental health conditions.

American actor James Spader has also spoken about his OCD. In 2014, when interviewed for Rolling Stone he said: "I'm obsessive-compulsive. I have very, very strong obsessive-compulsive issues. I'm very particular. ... It's very hard for me, you know? It makes you very addictive in behavior, because routine and ritual become entrenched. But in work, it manifests itself in obsessive attention to detail and fixation. It serves my work very well: Things don't slip by. But I'm not very easygoing.

In 2022 the president of Chile Gabriel Boric stated that he had OCD, saying: "I have an obsessive–compulsive disorder that's completely under control. Thank God I've been able to undergo treatment and it doesn't make me unable to carry out my responsibilities as the President of the Republic."

In a documentary released in 2023, David Beckham shared details about his compelling cleaning rituals, need for symmetry in the fridge, and the impact of OCD on his life.

Society and culture

This ribbon represents trichotillomania and other body-focused repetitive behaviors.

Art, entertainment and media

Movies and television shows may portray idealized or incomplete representations of disorders such as OCD. Compassionate and accurate literary and on-screen depictions may help counteract the potential stigma associated with an OCD diagnosis, and lead to increased public awareness, understanding and sympathy for such disorders.

  • The play and film adaptations of The Odd Couple based around the character of Felix, who shows some of the common symptoms of OCD.
  • In the film As Good as It Gets (1997), actor Jack Nicholson portrays a man with OCD who performs ritualistic behaviors that disrupt his life.
  • The film Matchstick Men (2003) portrays a con man named Roy (Nicolas Cage) with OCD who opens and closes doors three times while counting aloud before he can walk through them.
  • In the television series Monk (2002–2009), the titular character Adrian Monk fears both human contact and dirt.
  • The one-man show The Life and Slimes of Marc Summers (2016), a stage adaptation of Marc Summers' 1999 memoir which recounts how OCD affected his entertainment career.
  • In the novel Turtles All the Way Down (2017) by John Green, teenage main character Aza Holmes struggles with OCD that manifests as a fear of the human microbiome. Throughout the story, Aza repeatedly opens an unhealed callus on her finger to drain out what she believes are pathogens. The novel is based on Green's own experiences with OCD. He explained that Turtles All the Way Down is intended to show how "most people with chronic mental illnesses also live long, fulfilling lives".
  • The British TV series Pure (2019) stars Charly Clive as a 24-year-old Marnie who is plagued by disturbing sexual thoughts, as a kind of primarily obsessional obsessive compulsive disorder.

Research

The naturally occurring sugar inositol has been suggested as a treatment for OCD.

μ-Opioids agonists, such as hydrocodone and tramadol, may improve OCD symptoms. Administration of opiate treatment may be contraindicated in individuals concurrently taking CYP2D6 inhibitors such as fluoxetine and paroxetine.

Much current research is devoted to the therapeutic potential of the agents that affect the release of the neurotransmitter glutamate or the binding to its receptors. These include riluzole, memantine, gabapentin, N-acetylcysteine, topiramate and lamotrigine. Research on the potential for other supplements, such as milk thistle, to help with OCD and various neurological disorders, is ongoing.

Hercule Poirot

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Hercule_Poirot
Hercule Poirot
First appearance
Last appearanceCurtain (1975, by Agatha Christie)
Created byAgatha Christie
Portrayed byCharles Laughton
Francis L. Sullivan
Austin Trevor
Orson Welles
Harold Huber
Richard Williams
John Malkovich
José Ferrer
Martin Gabel
Tony Randall
Albert Finney
Dudley Jones
Peter Ustinov
Ian Holm
David Suchet
John Moffatt
Maurice Denham
Peter Sallis
Konstantin Raikin
Alfred Molina
Robert Powell
Jason Durr
Kenneth Branagh
Anthony O'Donnell
Shirō Itō (Takashi Akafuji)
Mansai Nomura (Takeru Suguro)
Tom Conti
Pál Mácsai
Voiced byKōtarō Satomi
In-universe information
GenderMale
OccupationPrivate investigator
Police officer (former occupation)
FamilyJules-Louis Poirot (father)
Godelieve Poirot (mother)
ReligionCatholic
NationalityBelgian

Hercule Poirot (UK: /ˈɛərkjuːl ˈpwɑːr/, US: /hɜːrˈkjuːl pwɑːˈr/) is a fictional Belgian detective created by British writer Agatha Christie. Poirot is one of Christie's most famous and long-running characters, appearing in 33 novels, two plays (Black Coffee and Alibi), and 51 short stories published between 1920 and 1975.

Poirot has been portrayed on radio, in film and on television by various actors, including Austin Trevor, John Moffatt, Albert Finney, Peter Ustinov, Ian Holm, Tony Randall, Alfred Molina, Orson Welles, David Suchet, Kenneth Branagh, and John Malkovich.

Overview

Influences

Poirot's name was derived from two other fictional detectives of the time: Marie Belloc Lowndes' Hercule Popeau and Frank Howel Evans' Monsieur Poiret, a retired French police officer living in London. Evans' Jules Poiret "was small and rather heavyset, hardly more than five feet, but moved with his head held high. The most remarkable features of his head were the stiff military moustache. His apparel was neat to perfection, a little quaint and frankly dandified." He was accompanied by Captain Harry Haven, who had returned to London from a Colombian business venture ended by a civil war. 

A more obvious influence on the early Poirot stories is that of Arthur Conan Doyle. In An Autobiography, Christie states, "I was still writing in the Sherlock Holmes tradition – eccentric detective, stooge assistant, with a Lestrade-type Scotland Yard detective, Inspector Japp".[a] Conan Doyle acknowledged basing his detective stories on the model of Edgar Allan Poe's C. Auguste Dupin and his anonymous narrator, and basing his character Sherlock Holmes on Joseph Bell, who in his use of "ratiocination" prefigured Poirot's reliance on his "little grey cells". Poirot also bears a striking resemblance to A. E. W. Mason's fictional detective Inspector Hanaud of the French Sûreté, who first appeared in the 1910 novel At the Villa Rose and predates the first Poirot novel by 10 years.

Christie's Poirot was clearly the result of her early development of the detective in her first book, written in 1916 and published in 1920. The large number of refugees in the country who had fled the German invasion of Belgium in August to November 1914 served as a plausible explanation of why such a skilled detective would be available to solve mysteries at an English country house. At the time of Christie's writing, it was considered patriotic to express sympathy towards the Belgians, since the invasion of their country had constituted Britain's casus belli for entering World War I, and British wartime propaganda emphasised the "Rape of Belgium".

Popularity

Poirot first appeared in The Mysterious Affair at Styles, published in 1920, and exited in Curtain, published in 1975. Following the latter, Poirot was the only fictional character to receive an obituary on the front page of The New York Times.

By 1930, Agatha Christie found Poirot "insufferable", and by 1960 she felt that he was a "detestable, bombastic, tiresome, ego-centric little creep". Despite this, Poirot remained an exceedingly popular character with the general public. Christie later stated that she refused to kill him off, claiming that it was her duty to produce what the public liked.

Appearance and proclivities

Captain Arthur Hastings's first description of Poirot:

He was hardly more than five feet four inches but carried himself with great dignity. His head was exactly the shape of an egg, and he always perched it a little on one side. His moustache was very stiff and military. Even if everything on his face was covered, the tips of moustache and the pink-tipped nose would be visible. The neatness of his attire was almost incredible; I believe a speck of dust would have caused him more pain than a bullet wound. Yet this quaint dandified little man who, I was sorry to see, now limped badly, had been in his time one of the most celebrated members of the Belgian police.

Agatha Christie's initial description of Poirot in Murder on the Orient Express:

By the step leading up into the sleeping-car stood a young French lieutenant, resplendent in uniform, conversing with a small man [Hercule Poirot] muffled up to the ears of whom nothing was visible but a pink-tipped nose and the two points of an upward-curled moustache. 

In the later books, his limp is not mentioned, suggesting it may have been a temporary wartime injury. (In Curtain, Poirot admits he was wounded when he first came to England.) Poirot has green eyes that are repeatedly described as shining "like a cat's" when he is struck by a clever idea, and dark hair, which he dyes later in life. In Curtain, he admits to Hastings that he wears a wig and a false moustache. However, in many of his screen incarnations, he is bald or balding.

Frequent mention is made of his patent leather shoes, damage to which is frequently a source of misery for him, but comical for the reader. Poirot's appearance, regarded as fastidious during his early career, later falls hopelessly out of fashion.

Among Poirot's most significant personal attributes is the sensitivity of his stomach:

The plane dropped slightly. "Mon estomac," thought Hercule Poirot, and closed his eyes determinedly.

He suffers from sea sickness, and, in Death in the Clouds, he states that his air sickness prevents him from being more alert at the time of the murder. Later in his life, we are told:

Always a man who had taken his stomach seriously, he was reaping his reward in old age. Eating was not only a physical pleasure, it was also an intellectual research.

Poirot is extremely punctual and carries a pocket watch almost to the end of his career. He is also particular about his personal finances, preferring to keep a bank balance of 444 pounds, 4 shillings, and 4 pence. Actor David Suchet, who portrayed Poirot on television, said "there's no question he's obsessive-compulsive". Film portrayer Kenneth Branagh said that he "enjoyed finding the sort of obsessive-compulsive" in Poirot.

As mentioned in Curtain and The Clocks, he is fond of classical music, particularly Mozart and Bach.

Methods

In The Mysterious Affair at Styles, Poirot operates as a fairly conventional, clue-based and logical detective; reflected in his vocabulary by two common phrases: his use of "the little grey cells" and "order and method". Hastings is irritated by the fact that Poirot sometimes conceals important details of his plans, as in The Big Four. In this novel, Hastings is kept in the dark throughout the climax. This aspect of Poirot is less evident in the later novels, partly because there is rarely a narrator to mislead.

In Murder on the Links, still largely dependent on clues himself, Poirot mocks a rival "bloodhound" detective who focuses on the traditional trail of clues established in detective fiction (e.g., Sherlock Holmes depending on footprints, fingerprints, and cigar ash). From this point on, Poirot establishes his psychological bona fides. Rather than painstakingly examining crime scenes, he enquires into the nature of the victim or the psychology of the murderer. He predicates his actions in the later novels on his underlying assumption that particular crimes are committed by particular types of people.

Poirot focuses on getting people to talk. In the early novels, he casts himself in the role of "Papa Poirot", a benign confessor, especially to young women. In later works, Christie made a point of having Poirot supply false or misleading information about himself or his background to assist him in obtaining information. In The Murder of Roger Ackroyd, Poirot speaks of a non-existent mentally disabled nephew to uncover information about homes for the mentally unfit. In Dumb Witness, Poirot invents an elderly invalid mother as a pretence to investigate local nurses. In The Big Four, Poirot pretends to have (and poses as) an identical twin brother named Achille: however, this brother was mentioned again in The Labours of Hercules.

"If I remember rightly – though my memory isn't what it was – you also had a brother called Achille, did you not?" Poirot's mind raced back over the details of Achille Poirot's career. Had all that really happened? "Only for a short space of time," he replied.

Poirot is also willing to appear more foreign or vain in an effort to make people underestimate him. He admits as much:

It is true that I can speak the exact, the idiomatic English. But, my friend, to speak the broken English is an enormous asset. It leads people to despise you. They say – a foreigner – he can't even speak English properly. ... Also I boast! An Englishman he says often, "A fellow who thinks as much of himself as that cannot be worth much." ... And so, you see, I put people off their guard.

He also has a tendency to refer to himself in the third person.

In later novels, Christie often uses the word mountebank when characters describe Poirot, showing that he has successfully passed himself off as a charlatan or fraud.

Poirot's investigating techniques assist him solving cases; "For in the long run, either through a lie, or through truth, people were bound to give themselves away..." At the end, Poirot usually reveals his description of the sequence of events and his deductions to a room of suspects, often leading to the culprit's apprehension.

Life

A statuette of Poirot in Ellezelles, Belgium

Origins

Christie was purposely vague about Poirot's origins, as he is thought to be an elderly man even in the early novels. In An Autobiography, she admitted that she already imagined him to be an old man in 1920. At the time, however, she did not know that she would write works featuring him for decades to come.

A brief passage in The Big Four provides original information about Poirot's birth or at least childhood in or near the town of Spa, Belgium: "But we did not go into Spa itself. We left the main road and wound into the leafy fastnesses of the hills, till we reached a little hamlet and an isolated white villa high on the hillside." Christie strongly implies that this "quiet retreat in the Ardennes" near Spa is the location of the Poirot family home.

An alternative tradition holds that Poirot was born in the village of Ellezelles (province of Hainaut, Belgium). A few memorials dedicated to Hercule Poirot can be seen in the centre of this village. There appears to be no reference to this in Christie's writings, but the town of Ellezelles cherishes a copy of Poirot's birth certificate in a local memorial 'attesting' Poirot's birth, naming his father and mother as Jules-Louis Poirot and Godelieve Poirot.

Christie wrote that Poirot is a Catholic by birth, but not much is described about his later religious convictions, except sporadic references to his "going to church" and occasional invocations of "le bon Dieu".[b] Christie provides little information regarding Poirot's childhood, only mentioning in Three Act Tragedy that he comes from a large family with little wealth, and has at least one younger sister. Apart from French and English, Poirot is also fluent in German.

Policeman

Gustave ... was not a policeman. I have dealt with policemen all my life and I know. He could pass as a detective to an outsider but not to a man who was a policeman himself.

— Hercule Poirot, The Erymanthian Boar

Hercule Poirot was active in the Brussels police force by 1893. Very little mention is made about this part of his life, but in "The Nemean Lion" (1939) Poirot refers to a Belgian case of his in which "a wealthy soap manufacturer ... poisoned his wife in order to be free to marry his secretary". As Poirot was often misleading about his past to gain information, the truthfulness of that statement is unknown; it does, however, scare off a would-be wife-killer.

In the short story "The Chocolate Box" (1923), Poirot reveals to Captain Arthur Hastings an account of what he considers to be his only failure. Poirot admits that he has failed to solve a crime "innumerable" times:

I have been called in too late. Very often another, working towards the same goal, has arrived there first. Twice I have been struck down with illness just as I was on the point of success.

Nevertheless, he regards the 1893 case in "The Chocolate Box",

Inspector Japp offers some insight into Poirot's career with the Belgian police when introducing him to a colleague:

You've heard me speak of Mr Poirot? It was in 1904 he and I worked together – the Abercrombie forgery case – you remember he was run down in Brussels. Ah, those were the days Moosier. Then, do you remember "Baron" Altara? There was a pretty rogue for you! He eluded the clutches of half the police in Europe. But we nailed him in Antwerp – thanks to Mr. Poirot here.

In The Double Clue, Poirot mentions that he was Chief of Police of Brussels, until "the Great War" (World War I) forced him to leave for England.

Private detective

I had called in at my friend Poirot's rooms to find him sadly overworked. So much had he become the rage that every rich woman who had mislaid a bracelet or lost a pet kitten rushed to secure the services of the great Hercule Poirot. 

During World War I, Poirot left Belgium for England as a refugee, although he returned a few times. On 16 July 1916 he again met his lifelong friend, Captain Arthur Hastings, and solved the first of his cases to be published, The Mysterious Affair at Styles. It is clear that Hastings and Poirot are already friends when they meet in Chapter 2 of the novel, as Hastings tells Cynthia that he has not seen him for "some years". Agatha Christie's Poirot has Hastings reveal that they met on a shooting case where Hastings was a suspect.

Particulars such as the date of 1916 for the case and that Hastings had met Poirot in Belgium, are given in Curtain, Chapter 1. After that case, Poirot apparently came to the attention of the British secret service and undertook cases for the British government, including foiling the attempted abduction of the Prime Minister. Readers were told that the British authorities had learned of Poirot's keen investigative ability from certain members of Belgium's royal family.

Florin Court became the fictional residence of Agatha Christie's Poirot, known as "Whitehaven Mansions".

After the war, Poirot became a private detective and began undertaking civilian cases. He moved into what became both his home and work address, Flat 203 at 56B Whitehaven Mansions. Hastings first visits the flat when he returns to England in June 1935 from Argentina in The A.B.C. Murders, Chapter 1. The TV programmes place this in Florin Court, Charterhouse Square, in the wrong part of London.

According to Hastings, it was chosen by Poirot "entirely on account of its strict geometrical appearance and proportion" and described as the "newest type of service flat". His first case in this period was "The Affair at the Victory Ball", which allowed Poirot to enter high society and begin his career as a private detective.

Between the world wars, Poirot travelled all over Europe and the Middle East investigating crimes and solving murders. Most of his cases occurred during this time, and he was at the height of his powers at this point in his life. In The Murder on the Links, the Belgian pits his grey cells against a French murderer. In the Middle East, he solved the cases Death on the Nile and Murder in Mesopotamia with ease, and even survived An Appointment with Death. As he passed through Eastern Europe on his return trip, he solved The Murder on the Orient Express. He did not travel to Africa or Asia, probably to avoid seasickness.

It is this villainous sea that troubles me! The mal de mer – it is horrible suffering!

It was during this time he met the Countess Vera Rossakoff, a glamorous jewel thief. The history of the countess is, like Poirot's, steeped in mystery. She claims to have been a member of the Russian aristocracy before the Russian Revolution and suffered greatly as a result, but how much of that story is true is an open question. Even Poirot acknowledges that Rossakoff offered wildly varying accounts of her early life. Poirot later became smitten with the woman and allowed her to escape justice.

It is the misfortune of small, precise men always to hanker after large and flamboyant women. Poirot had never been able to rid himself of the fatal fascination that the countess held for him.

Although letting the countess escape was morally questionable, it was not uncommon. In The Nemean Lion, Poirot sided with the criminal, Miss Amy Carnaby, allowing her to evade prosecution by blackmailing his client Sir Joseph Hoggins, who, Poirot discovered, had plans to commit murder. Poirot even sent Miss Carnaby two hundred pounds as a final payoff prior to the conclusion of her dog kidnapping campaign. In The Murder of Roger Ackroyd, Poirot allowed the murderer to escape justice through suicide and then withheld the truth to spare the feelings of the murderer's relatives.

In The Augean Stables, he helped the government to cover up vast corruption. In Murder on the Orient Express, Poirot allowed the murderers to go free after discovering that twelve different people participated in the murder, each one stabbing the victim in a darkened carriage, after drugging him into unconsciousness so that there was no way for anyone to definitively determine which of them actually delivered the killing blow. The victim had committed a disgusting crime which led to the deaths of at least five people, and there was no question of his guilt, but he had been acquitted in America in a miscarriage of justice.

Considering it poetic justice that twelve jurors had acquitted him and twelve people had stabbed him, Poirot produced an alternative sequence of events to explain the death involving an unknown additional passenger on the train, with the medical examiner agreeing to doctor his own report to support this theory.

After his cases in the Middle East, Poirot returned to Britain. Apart from some of the so-called Labours of Hercules (see next section) he very rarely went abroad during his later career. He moved into Styles Court towards the end of his life.

While Poirot was usually paid handsomely by clients, he was also known to take on cases that piqued his curiosity, although they did not pay well.

Poirot shows a love of steam trains, which Christie contrasts with Hastings' love of autos: this is shown in The Plymouth Express, The Mystery of the Blue Train, Murder on the Orient Express, and The ABC Murders. In the TV series, steam trains are seen in nearly all of the episodes.

Retirement

That's the way of it. Just a case or two, just one case more – the Prima Donna's farewell performance won't be in it with yours, Poirot.

Confusion surrounds Poirot's retirement. Most of the cases covered by Poirot's private detective agency take place before his retirement to attempt to grow larger marrows, at which time he solves The Murder of Roger Ackroyd. It has been said that the twelve cases related in The Labours of Hercules (1947) must refer to a different retirement, but the fact that Poirot specifically says that he intends to grow marrows indicates that these stories also take place before Roger Ackroyd, and presumably Poirot closed his agency once he had completed them.

There is specific mention in "The Capture of Cerberus" of the twenty-year gap between Poirot's previous meeting with Countess Rossakoff and this one. If the Labours precede the events in Roger Ackroyd, then the Ackroyd case must have taken place around twenty years later than it was published, and so must any of the cases that refer to it. One alternative would be that having failed to grow marrows once, Poirot is determined to have another go, but this is specifically denied by Poirot himself.

In "The Erymanthian Boar", a character is said to have been turned out of Austria by the Nazis, implying that the events of The Labours of Hercules took place after 1937. Another alternative would be to suggest that the Preface to the Labours takes place at one date but that the labours are completed over a matter of twenty years. None of the explanations is especially attractive.

In terms of a rudimentary chronology, Poirot speaks of retiring to grow marrows in Chapter 18 of The Big Four (1927) which places that novel out of published order before Roger Ackroyd. He declines to solve a case for the Home Secretary because he is retired in Chapter One of Peril at End House (1932). He has certainly retired at the time of Three Act Tragedy (1935) but he does not enjoy his retirement and repeatedly takes cases thereafter when his curiosity is engaged.

He continues to employ his secretary, Miss Lemon, at the time of the cases retold in Hickory Dickory Dock and Dead Man's Folly, which take place in the mid-1950s. It is, therefore, better to assume that Christie provided no authoritative chronology for Poirot's retirement but assumed that he could either be an active detective, a consulting detective, or a retired detective as the needs of the immediate case required.

One consistent element about Poirot's retirement is that his fame declines during it, so that in the later novels he is often disappointed when characters, especially younger characters, recognise neither him nor his name:

"I should, perhaps, Madame, tell you a little more about myself. I am Hercule Poirot."

The revelation left Mrs Summerhayes unmoved.

"What a lovely name," she said kindly. "Greek, isn't it?"

Post–World War II

He, I knew, was not likely to be far from his headquarters. The time when cases had drawn him from one end of England to the other was past.

— Hastings

Poirot is less active during the cases that take place at the end of his career. Beginning with Three Act Tragedy (1934), Christie had perfected during the inter-war years a subgenre of Poirot novel in which the detective himself spent much of the first third of the novel on the periphery of events. In novels such as Taken at the Flood, After the Funeral, and Hickory Dickory Dock, he is even less in evidence, frequently passing the duties of main interviewing detective to a subsidiary character. In Cat Among the Pigeons, Poirot's entrance is so late as to be almost an afterthought. Whether this was a reflection of his age or of Christie's distaste for him, is impossible to assess. Crooked House (1949) and Ordeal by Innocence (1957), which could easily have been Poirot novels, represent a logical endpoint of the general diminution of his presence in such works.

Towards the end of his career, it becomes clear that Poirot's retirement is no longer a convenient fiction. He assumes a genuinely inactive lifestyle during which he concerns himself with studying famous unsolved cases of the past and reading detective novels. He even writes a book about mystery fiction in which he deals sternly with Edgar Allan Poe and Wilkie Collins. In the absence of a more appropriate puzzle, he solves such inconsequential domestic riddles as the presence of three pieces of orange peel in his umbrella stand.

Poirot, and, it is reasonable to suppose, his creator becomes increasingly bemused by the vulgarism of the up-and-coming generation's young people. In Hickory Dickory Dock, he investigates the strange goings-on in a student hostel, while in Third Girl (1966) he is forced into contact with the smart set of Chelsea youths. In the growing drug and pop culture of the sixties, he proves himself once again but has become heavily reliant on other investigators, especially the private investigator, Mr. Goby, who provide him with the clues that he can no longer gather for himself.

You're too old. Nobody told me you were so old. I really don't want to be rude but – there it is. You're too old. I'm really very sorry.

— Norma Restarick to Poirot in Third Girl, Chapter 1

Notably, during this time his physical characteristics also change dramatically, and by the time Arthur Hastings meets Poirot again in Curtain, he looks very different from his previous appearances, having become thin with age and with obviously dyed hair.

Death

On the ITV television series, Poirot died in October 1949 from complications of a heart condition at the end of Curtain. This took place at Styles Court, the scene of his first English case in 1916. In Christie's novels, he lived into the early 1970s, perhaps even until 1975 when Curtain was published.

In Curtain, Poirot himself became a murderer, in order to prevent further murders instigated by a man who manipulated others to kill for him, subtly and psychologically manipulating the moments where others desire to commit murder so that they carry out the crime when they might otherwise dismiss their thoughts as nothing more than a momentary passion. Poirot executed the man, as otherwise he would have continued his actions and never been convicted.

Poirot himself died shortly after having committed murder. He had moved his amyl nitrite pills out of his own reach, possibly because of guilt. Poirot himself noted that he wanted to kill his victim shortly before his own death so that he could avoid succumbing to the arrogance of the murderer, concerned that he might come to view himself as entitled to kill those whom he deemed necessary to eliminate.

It is revealed at the end of Curtain that he fakes his need for a wheelchair to fool people into believing that he is suffering from arthritis, to give the impression that he is more infirm than he is. His last recorded words are "Cher ami!", spoken to Hastings as the Captain left his room. The TV adaptation adds that as Poirot is dying alone, he whispers out his final prayer to God in these words: "Forgive me... forgive...". Poirot was buried at Styles, and his funeral was arranged by his best friend Hastings and Hastings' daughter Judith. Hastings reasoned, "Here was the spot where he had lived when he first came to this country. He was to lie here at the last."

Poirot's actual death and funeral occurred in Curtain, years after his retirement from the active investigation, but it was not the first time that Hastings attended the funeral of his best friend. In The Big Four (1927), Poirot feigned his death and subsequent funeral to launch a surprise attack on the Big Four.

Recurring characters

Captain Arthur Hastings

Hastings, a former British Army officer, meets Poirot during Poirot's years as a police officer in Belgium and almost immediately after they both arrive in England. He becomes Poirot's lifelong friend and appears in many cases. Poirot regards Hastings as a poor private detective, not particularly intelligent, yet helpful in his way of being fooled by the criminal or seeing things the way the average man would see them and for his tendency to unknowingly "stumble" onto the truth. Hastings marries and has four children – two sons and two daughters. As a loyal, albeit somewhat naïve companion, Hastings is to Poirot what Watson is to Sherlock Holmes.

Hastings is capable of great bravery and courage, facing death unflinchingly when confronted by The Big Four and displaying unwavering loyalty towards Poirot. However, when forced to choose between Poirot and his wife in that novel, he initially chooses to betray Poirot to protect his wife. Later, though, he tells Poirot to draw back and escape the trap.

The two are an airtight team until Hastings meets and marries Dulcie Duveen, a beautiful music hall performer half his age, after investigating the Murder on the Links. They later emigrated to Argentina, leaving Poirot behind as a "very unhappy old man". Poirot and Hastings reunite during the novels The Big Four, Peril at End House, The ABC Murders, Lord Edgware Dies, and Dumb Witness, when Hastings arrives in England for business, with Poirot noting in ABC Murders that he enjoys having Hastings over because he feels that he always has his most interesting cases with Hastings.

The two collaborate for the final time in Curtain when the seemingly-crippled Poirot asks Hastings to assist him in his final case. When the killer they are tracking nearly manipulates Hastings into committing murder, Poirot describes this in his final farewell letter to Hastings as the catalyst that prompted him to eliminate the man himself, as Poirot knew that his friend was not a murderer and refused to let a man capable of manipulating Hastings in such a manner go on.

Mrs Ariadne Oliver

Detective novelist Ariadne Oliver is Agatha Christie's humorous self-caricature. Like Christie, she is not overly fond of the detective whom she is most famous for creating–in Ariadne's case, Finnish sleuth Sven Hjerson. We never learn anything about her husband, but we do know that she hates alcohol and public appearances and has a great fondness for apples, until she is put off them by the events of Hallowe'en Party. She has a habit of constantly changing her hairstyle. In every appearance by her much is made of her clothes and hats. Her maid Maria prevents the public adoration from becoming too much of a burden on her employer but does nothing to prevent her from becoming too much of a burden on others.

She has authored more than 56 novels and greatly dislikes people modifying her characters. She is the only one in Poirot's universe to have noted that "It's not natural for five or six people to be on the spot when B is murdered and all have a motive for killing B." She first met Poirot in the story Cards on the Table and has bothered him ever since.

Miss Felicity Lemon

Poirot's secretary, Miss Felicity Lemon, has few human weaknesses. The only mistakes she makes within the series are a typing error during the events of Hickory Dickory Dock and the mis-mailing of an electricity bill, although she was worried about strange events surrounding her sister who worked at a student hostel at the time. Poirot described her as being "Unbelievably ugly and incredibly efficient. Anything that she mentioned as worth consideration usually was worth consideration." She is an expert on nearly everything and plans to create the perfect filing system.

In The Agatha Christie Hour, she was portrayed by Angela Easterling, while in Agatha Christie's Poirot she was portrayed by Pauline Moran (where she was shown to be efficient, prim and modest, but not remotely "unbelievably ugly".) On a number of occasions, she joins Poirot in his inquiries or seeks out answers alone at his request.

Chief Inspector James Harold Japp

Japp is a Scotland Yard Inspector and appears in many of the stories trying to solve cases that Poirot is working on. Japp is outgoing, loud, and sometimes inconsiderate by nature, and his relationship with the refined Belgian is one of the stranger aspects of Poirot's world. He first met Poirot in Belgium in 1904, during the Abercrombie Forgery. Later that year they joined forces again to hunt down a criminal known as Baron Altara. They also meet in England where Poirot often helps Japp and lets him take credit in return for special favours. These favours usually entail Poirot being supplied with other interesting cases.

In Agatha Christie's Poirot, Japp was portrayed by Philip Jackson. In the film, Thirteen at Dinner (1985), adapted from Lord Edgware Dies, the role of Japp was taken by the actor David Suchet, who would later star as Poirot in the ITV adaptations.

Major novels

The Poirot books take readers through the whole of his life in England, from the first book (The Mysterious Affair at Styles), where he is a refugee staying at Styles, to the last Poirot book (Curtain), where he visits Styles before his death. In between, Poirot solves cases outside England as well, including his most famous case, Murder on the Orient Express (1934).

Hercule Poirot became famous in 1926 with the publication of The Murder of Roger Ackroyd, whose surprising solution proved controversial. The novel is still among the most famous of all detective novels: Edmund Wilson alludes to it in the title of his well-known attack on detective fiction, "Who Cares Who Killed Roger Ackroyd?" Aside from Roger Ackroyd, the most critically acclaimed Poirot novels appeared from 1932 to 1942, including Murder on the Orient Express (1934); The ABC Murders (1935); Cards on the Table (1936); and Death on the Nile (1937), a tale of multiple murders upon a Nile steamer. Death on the Nile was judged by the famed detective novelist John Dickson Carr to be among the ten greatest mystery novels of all time.

The 1942 novel Five Little Pigs (a.k.a. Murder in Retrospect), in which Poirot investigates a murder committed sixteen years before by analysing various accounts of the tragedy, has been called "the best Christie of all" by critic and mystery novelist Robert Barnard.

In 2014, the Poirot canon was added to by Sophie Hannah, the first author to be commissioned by the Christie estate to write an original story. The novel was called The Monogram Murders, and was set in the late 1920s, placing it chronologically between The Mystery of the Blue Train and Peril at End House. A second Hannah-penned Poirot came out in 2016, called Closed Casket, and a third, The Mystery of Three Quarters, in 2018.

Portrayals

Stage

The first actor to portray Poirot was Charles Laughton. He appeared on the West End in 1928 in the play Alibi which had been adapted by Michael Morton from the novel The Murder of Roger Ackroyd. In 1932, the play was performed as The Fatal Alibi on Broadway. Another Poirot play, Black Coffee opened in London at the Embassy Theatre on 8 December 1930 and starred Francis L. Sullivan as Poirot.

Another production of Black Coffee ran in Dublin, Ireland from 23 to 28 June 1931, starring Robert Powell. American playwright Ken Ludwig adapted Murder on the Orient Express into a play, which premiered at the McCarter Theatre in Princeton, New Jersey on 14 March 2017. It starred Allan Corduner in the role of Hercule Poirot.

Film

Austin Trevor

Austin Trevor debuted the role of Poirot on screen in the 1931 British film Alibi. The film was based on the stage play. Trevor reprised the role of Poirot twice, in Black Coffee and Lord Edgware Dies. Trevor said once that he was probably cast as Poirot simply because he could do a French accent. Notably, Trevor's Poirot did not have a moustache. Leslie S. Hiscott directed the first two films, and Henry Edwards took over for the third.

Tony Randall

Tony Randall portrayed Poirot in The Alphabet Murders, a 1965 film also known as The ABC Murders. This was more a satire of Poirot than a straightforward adaptation and was greatly changed from the original. Much of the story, set in modern times, was played for comedy, with Poirot investigating the murders while evading the attempts by Hastings (Robert Morley) and the police to get him out of England and back to Belgium.

Albert Finney

Albert Finney as Poirot in the 1974 film, Murder on the Orient Express

Albert Finney played Poirot in 1974 in the cinematic version of Murder on the Orient Express. As of now, Finney is the only actor to receive an Academy Award nomination for playing Poirot, though he did not win.

Peter Ustinov

Peter Ustinov as Poirot in a 1982 adaptation of the novel Evil Under the Sun

Peter Ustinov played Poirot six times, starting with Death on the Nile (1978). He reprised the role in Evil Under the Sun (1982) and Appointment with Death (1988).

Christie's daughter Rosalind Hicks observed Ustinov during a rehearsal and said, "That's not Poirot! He isn't at all like that!" Ustinov overheard and remarked "He is now!"

He appeared again as Poirot in three television films: Thirteen at Dinner (1985), Dead Man's Folly (1986), and Murder in Three Acts (1986). Earlier adaptations were set during the time in which the novels were written, but these television films were set in the contemporary era. The first of these was based on Lord Edgware Dies and was made by Warner Bros. It also starred Faye Dunaway, with David Suchet as Inspector Japp, just before Suchet began to play Poirot. David Suchet considers his performance as Japp to be "possibly the worst performance of [his] career".

Kenneth Branagh

Kenneth Branagh played Poirot in film adaptations of Murder on the Orient Express in 2017, Death on the Nile in 2022, and A Haunting in Venice, based on the novel Hallowe'en Party, in 2023. Branagh directed all three and co-produced them alongside Ridley Scott. They were all written by Michael Green.

Other

  • Anatoly Ravikovich, Zagadka Endkhauza (End House Mystery) (1989; based on "Peril at End House")
  • Pál Mácsai, A titokzatos stylesi eset (The Mysterious Affair at Styles) (2023)

Television

David Suchet

David Suchet starred as Poirot in the ITV series Agatha Christie's Poirot from 1989 until June 2013, when he announced that he was bidding farewell to the role. "No one could've guessed then that the series would span a quarter-century or that the classically trained Suchet would complete the entire catalogue of whodunits featuring the eccentric Belgian investigator, including 33 novels and dozens of short stories." His final appearance in the show was in an adaptation of Curtain, aired on 13 November 2013.

The writers of the "Binge!" article of Entertainment Weekly December 2014/January 2015) picked Suchet as "Best Poirot" in the "Hercule Poirot & Miss Marple" timeline.

The episodes were shot in various locations in the UK and abroad (for example "Triangle at Rhodes" and "Problem at Sea"), whilst other scenes were shot at Twickenham Studios.

Other

Anime

In 2004, the Japanese public broadcaster NHK produced a 39-episode anime series titled Agatha Christie's Great Detectives Poirot and Marple, as well as a manga series under the same title released in 2005. The series, adapting several of the best-known Poirot and Marple stories, ran from 4 July 2004 through 15 May 2005, and in repeated reruns on NHK and other networks in Japan. Poirot was voiced by Kōtarō Satomi and Miss Marple was voiced by Kaoru Yachigusa.

Radio

From 1985 to 2007, BBC Radio 4 produced a series of twenty-seven adaptations of Poirot novels and short stories, adapted by Michael Bakewell and directed by Enyd Williams. Twenty five starred John Moffatt as Poirot; Maurice Denham and Peter Sallis played Poirot on BBC Radio 4 in the first two adaptations, The Mystery of the Blue Train and in Hercule Poirot's Christmas respectively.

In 1939, Orson Welles and the Mercury Players dramatised Roger Ackroyd on CBS's Campbell Playhouse.

On 6 October 1942, the Mutual radio series Murder Clinic broadcast "The Tragedy at Marsden Manor" starring Maurice Tarplin as Poirot.

A 1945 radio series of at least 13 original half-hour episodes (none of which apparently adapt any Christie stories) transferred Poirot from London to New York and starred character actor Harold Huber, perhaps better known for his appearances as a police officer in various Charlie Chan films. On 22 February 1945, "speaking from London, Agatha Christie introduced the initial broadcast of the Poirot series via shortwave".

An adaptation of Murder in the Mews was broadcast on the BBC Light Programme in March 1955 starring Richard Bebb as Poirot; this program was thought lost, but was discovered in the BBC archives in 2015.

Other audio

In 2017, Audible released an original audio adaptation of Murder on the Orient Express starring Tom Conti as Poirot. The cast included Jane Asher as Mrs. Hubbard, Jay Benedict as Monsieur Bouc, Ruta Gedmintas as Countess Andrenyi, Sophie Okonedo as Mary Debenham, Eddie Marsan as Ratchett, Walles Hamonde as Hector MacQueen, Paterson Joseph as Colonel Arbuthnot, Rula Lenska as Princess Dragimiroff and Art Malik as the Narrator. According to the Publisher's Summary on Audible.com, "sound effects [were] recorded on the Orient Express itself."

In 2021, L.A. Theatre Works produced an adaptation of The Murder on the Links, dramatised by Kate McAll. Alfred Molina starred as Poirot, with Simon Helberg as Hastings.

Video games

In the video games Agatha Christie - Hercule Poirot: The First Cases and Agatha Christie - Hercule Poirot: The London Case, Poirot is voiced by Will De Renzy-Martin.

Parodies and references

Parodies of Hercule Poirot have appeared in a number of movies, including Revenge of the Pink Panther, where Poirot makes a cameo appearance in a mental asylum, portrayed by Andrew Sachs and claiming to be "the greatest detective in all of France, the greatest in all the world"; Neil Simon's Murder by Death, where "Milo Perrier" is played by American actor James Coco; the 1977 film The Strange Case of the End of Civilization as We Know It (1977); the film Spice World, where Hugh Laurie plays Poirot; and in Sherlock Holmes: The Awakened, Poirot appears as a young boy on the train transporting Holmes and Watson. Holmes helps the boy in opening a puzzle-box, with Watson giving the boy advice about using his "little grey cells".

In the book series Geronimo Stilton, the character Hercule Poirat is inspired by Hercule Poirot.

The Belgian brewery Brasserie Ellezelloise makes a stout called Hercule with a moustachioed caricature of Hercule Poirot on the label.

In season 2, episode 4 of TVFPlay's Indian web series Permanent Roommates, one of the characters refers to Hercule Poirot as her inspiration while she attempts to solve the mystery of the cheating spouse. Throughout the episode, she is mocked as Hercule Poirot and Agatha Christie by the suspects. TVFPlay also telecasted a spoof of Indian TV suspense drama CID as "Qissa Missing Dimaag Ka: C.I.D Qtiyapa". In the first episode, when Ujjwal is shown to browse for the best detectives of the world, David Suchet appears as Poirot in his search.

Brezhnev Doctrine

From Wikipedia, the free encyclopedia Eastern Bloc : the USSR and its satelli...