From Wikipedia, the free encyclopedia
 
Mental disorder
Other namesPsychiatric disorder, psychological disorder, mental illness, mental disease, mental breakdown, nervous breakdown, mental health conditions
SpecialtyPsychiatry
SymptomsAgitation, anxiety, depression, mania, paranoia, psychosis
ComplicationsCognitive impairment, social problems, suicide
TypesAnxiety disorders, eating disorders, mood disorders, personality disorders, psychotic disorders, substance use disorders
CausesGenetic and environmental factors
TreatmentPsychotherapy, medications
MedicationAntidepressants, antipsychotics, anxiolytics, mood stabilizers, stimulants
Frequency18% per year (United States)

A mental disorder, also called a mental illness or psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. Such features may be persistent, relapsing and remitting, or occur as single episodes. Many disorders have been described, with signs and symptoms that vary widely between specific disorders. Such disorders may be diagnosed by a mental health professional, usually a clinical psychologist or psychiatrist.

The causes of mental disorders are often unclear. Theories may incorporate findings from a range of fields. Mental disorders are usually defined by a combination of how a person behaves, feels, perceives, or thinks. This may be associated with particular regions or functions of the brain, often in a social context. A mental disorder is one aspect of mental health. Cultural and religious beliefs, as well as social norms, should be taken into account when making a diagnosis.

Services are based in psychiatric hospitals or in the community, and assessments are carried out by mental health professionals such as psychiatrists, psychologists, psychiatric nurses and clinical social workers, using various methods such as psychometric tests but often relying on observation and questioning. Treatments are provided by various mental health professionals. Psychotherapy and psychiatric medication are two major treatment options. Other treatments include lifestyle changes, social interventions, peer support, and self-help. In a minority of cases, there might be involuntary detention or treatment. Prevention programs have been shown to reduce depression.

In 2019, common mental disorders around the globe include depression, which affects about 264 million, bipolar disorder, which affects about 45 million, dementia, which affects about 50 million, and schizophrenia and other psychoses, which affects about 20 million people. Neurodevelopmental disorders include intellectual disability and autism spectrum disorders which usually arise in infancy or childhood. Stigma and discrimination can add to the suffering and disability associated with mental disorders, leading to various social movements attempting to increase understanding and challenge social exclusion.

Definition

The definition and classification of mental disorders are key issues for researchers as well as service providers and those who may be diagnosed. For a mental state to classify as a disorder, it generally needs to cause dysfunction. Most international clinical documents use the term mental "disorder", while "illness" is also common. It has been noted that using the term "mental" (i.e., of the mind) is not necessarily meant to imply separateness from the brain or body.

According to DSM-IV, a mental disorder is a psychological syndrome or pattern which is associated with distress (e.g. via a painful symptom), disability (impairment in one or more important areas of functioning), increased risk of death, or causes a significant loss of autonomy; however it excludes normal responses such as grief from loss of a loved one and also excludes deviant behavior for political, religious, or societal reasons not arising from a dysfunction in the individual.

DSM-IV predicates the definition with caveats, stating that, as in the case with many medical terms, mental disorder "lacks a consistent operational definition that covers all situations", noting that different levels of abstraction can be used for medical definitions, including pathology, symptomology, deviance from a normal range, or etiology, and that the same is true for mental disorders so that sometimes one type of definition is appropriate, and sometimes another, depending on the situation.

In 2013, the American Psychiatric Association (APA) redefined mental disorders in the DSM-5 as "a syndrome characterized by clinically significant disturbance in an individual's cognition, emotion regulation, or behavior that reflects a dysfunction in the psychological, biological, or developmental processes underlying mental functioning." The final draft of ICD-11 contains a very similar definition.

The terms "mental breakdown" or "nervous breakdown" may be used by the general population to mean a mental disorder. The terms "nervous breakdown" and "mental breakdown" have not been formally defined through a medical diagnostic system such as the DSM-5 or ICD-10, and are nearly absent from scientific literature regarding mental illness. Although "nervous breakdown" is not rigorously defined, surveys of laypersons suggest that the term refers to a specific acute time-limited reactive disorder, involving symptoms such as anxiety or depression, usually precipitated by external stressors. Many health experts today refer to a nervous breakdown as a mental health crisis.

Nervous illness

Additionally to the concept of mental disorder, some people have argued for a return to the old-fashioned concept of nervous illness. In How Everyone Became Depressed: The Rise and Fall of the Nervous Breakdown (2013), Edward Shorter, a professor of psychiatry and the history of medicine, says:

About half of them are depressed. Or at least that is the diagnosis that they got when they were put on antidepressants. ... They go to work but they are unhappy and uncomfortable; they are somewhat anxious; they are tired; they have various physical pains—and they tend to obsess about the whole business. There is a term for what they have, and it is a good old-fashioned term that has gone out of use. They have nerves or a nervous illness. It is an illness not just of mind or brain, but a disorder of the entire body. ... We have a package here of five symptoms—mild depression, some anxiety, fatigue, somatic pains, and obsessive thinking. ... We have had nervous illness for centuries. When you are too nervous to function ... it is a nervous breakdown. But that term has vanished from medicine, although not from the way we speak.... The nervous patients of yesteryear are the depressives of today. That is the bad news.... There is a deeper illness that drives depression and the symptoms of mood. We can call this deeper illness something else, or invent a neologism, but we need to get the discussion off depression and onto this deeper disorder in the brain and body. That is the point.

— Edward Shorter, Faculty of Medicine, the University of Toronto

In eliminating the nervous breakdown, psychiatry has come close to having its own nervous breakdown.

— David Healy, MD, FRCPsych, Professor of Psychiatry, University of Cardiff, Wales

Nerves stand at the core of common mental illness, no matter how much we try to forget them.

— Peter J. Tyrer, FMedSci, Professor of Community Psychiatry, Imperial College, London

"Nervous breakdown" is a pseudo-medical term to describe a wealth of stress-related feelings and they are often made worse by the belief that there is a real phenomenon called "nervous breakdown".

— Richard E. Vatz, co-author of explication of views of Thomas Szasz in "Thomas Szasz: Primary Values and Major Contentions"

Classifications

There are currently two widely established systems that classify mental disorders:

Both of these list categories of disorder and provide standardized criteria for diagnosis. They have deliberately converged their codes in recent revisions so that the manuals are often broadly comparable, although significant differences remain. Other classification schemes may be used in non-western cultures, for example, the Chinese Classification of Mental Disorders, and other manuals may be used by those of alternative theoretical persuasions, such as the Psychodynamic Diagnostic Manual. In general, mental disorders are classified separately from neurological disorders, learning disabilities or intellectual disability.

Unlike the DSM and ICD, some approaches are not based on identifying distinct categories of disorder using dichotomous symptom profiles intended to separate the abnormal from the normal. There is significant scientific debate about the relative merits of categorical versus such non-categorical (or hybrid) schemes, also known as continuum or dimensional models. A spectrum approach may incorporate elements of both.

In the scientific and academic literature on the definition or classification of mental disorder, one extreme argues that it is entirely a matter of value judgements (including of what is normal) while another proposes that it is or could be entirely objective and scientific (including by reference to statistical norms). Common hybrid views argue that the concept of mental disorder is objective even if only a "fuzzy prototype" that can never be precisely defined, or conversely that the concept always involves a mixture of scientific facts and subjective value judgments. Although the diagnostic categories are referred to as 'disorders', they are presented as medical diseases, but are not validated in the same way as most medical diagnoses. Some neurologists argue that classification will only be reliable and valid when based on neurobiological features rather than clinical interview, while others suggest that the differing ideological and practical perspectives need to be better integrated.

The DSM and ICD approach remains under attack both because of the implied causality model and because some researchers believe it better to aim at underlying brain differences which can precede symptoms by many years.

Dimensional models

The high degree of comorbidity between disorders in categorical models such as the DSM and ICD have led some to propose dimensional models. Studying comorbidity between disorders have demonstrated two latent (unobserved) factors or dimensions in the structure of mental disorders that are thought to possibly reflect etiological processes. These two dimensions reflect a distinction between internalizing disorders, such as mood or anxiety symptoms, and externalizing disorders such as behavioral or substance use symptoms. A single general factor of psychopathology, similar to the g factor for intelligence, has been empirically supported. The p factor model supports the internalizing-externalizing distinction, but also supports the formation of a third dimension of thought disorders such as schizophrenia. Biological evidence also supports the validity of the internalizing-externalizing structure of mental disorders, with twin and adoption studies supporting heritable factors for externalizing and internalizing disorders.

Disorders

There are many different categories of mental disorder, and many different facets of human behavior and personality that can become disordered.

Anxiety disorder

Anxiety disorder: Anxiety or fear that interferes with normal functioning may be classified as an anxiety disorder. Commonly recognized categories include specific phobias, generalized anxiety disorder, social anxiety disorder, panic disorder, agoraphobia, obsessive-compulsive disorder and post-traumatic stress disorder.

Mood disorder

Mood disorder: Other affective (emotion/mood) processes can also become disordered. Mood disorder involving unusually intense and sustained sadness, melancholia, or despair is known as major depression (also known as unipolar or clinical depression). Milder but still prolonged depression can be diagnosed as dysthymia. Bipolar disorder (also known as manic depression) involves abnormally "high" or pressured mood states, known as mania or hypomania, alternating with normal or depressed moods. The extent to which unipolar and bipolar mood phenomena represent distinct categories of disorder, or mix and merge along a dimension or spectrum of mood, is subject to some scientific debate.

Psychotic disorder

Psychotic disorder: Patterns of belief, language use and perception of reality can become dysregulated (e.g., delusions, thought disorder, hallucinations). Psychotic disorders in this domain include schizophrenia, and delusional disorder. Schizoaffective disorder is a category used for individuals showing aspects of both schizophrenia and affective disorders. Schizotypy is a category used for individuals showing some of the characteristics associated with schizophrenia but without meeting cutoff criteria.

Personality disorder

Personality disorder: Personality—the fundamental characteristics of a person that influence thoughts and behaviors across situations and time—may be considered disordered if judged to be abnormally rigid and maladaptive. Although treated separately by some, the commonly used categorical schemes include them as mental disorders, albeit on a separate axis II in the case of the DSM-IV. A number of different personality disorders are listed, including those sometimes classed as eccentric, such as paranoid, schizoid and schizotypal personality disorders; types that have described as dramatic or emotional, such as antisocial, borderline, histrionic or narcissistic personality disorders; and those sometimes classed as fear-related, such as anxious-avoidant, dependent, or obsessive-compulsive personality disorders. Personality disorders, in general, are defined as emerging in childhood, or at least by adolescence or early adulthood. The ICD also has a category for enduring personality change after a catastrophic experience or psychiatric illness. If an inability to sufficiently adjust to life circumstances begins within three months of a particular event or situation, and ends within six months after the stressor stops or is eliminated, it may instead be classed as an adjustment disorder. There is an emerging consensus that personality disorders, similar to personality traits in general, incorporate a mixture of acute dysfunctional behaviors that may resolve in short periods, and maladaptive temperamental traits that are more enduring. Furthermore, there are also non-categorical schemes that rate all individuals via a profile of different dimensions of personality without a symptom-based cutoff from normal personality variation, for example through schemes based on dimensional models.

Eating disorder

Eating disorders involve disproportionate concern in matters of food and weight. Categories of disorder in this area include anorexia nervosa, bulimia nervosa, exercise bulimia or binge eating disorder.

Sleep disorder

Sleep disorders are associated with disruption to normal sleep patterns. A common sleep disorder is insomnia, which is described as difficulty falling and/or staying asleep.

Sexuality related

Sexual disorders include dyspareunia and various kinds of paraphilia (sexual arousal to objects, situations, or individuals that are considered abnormal or harmful to the person or others).

Other

Impulse control disorder: People who are abnormally unable to resist certain urges or impulses that could be harmful to themselves or others, may be classified as having an impulse control disorder, and disorders such as kleptomania (stealing) or pyromania (fire-setting). Various behavioral addictions, such as gambling addiction, may be classed as a disorder. Obsessive-compulsive disorder can sometimes involve an inability to resist certain acts but is classed separately as being primarily an anxiety disorder.

Substance use disorder: This disorder refers to the use of drugs (legal or illegal, including alcohol) that persists despite significant problems or harm related to its use. Substance dependence and substance abuse fall under this umbrella category in the DSM. Substance use disorder may be due to a pattern of compulsive and repetitive use of a drug that results in tolerance to its effects and withdrawal symptoms when use is reduced or stopped.

Dissociative disorder: People who suffer severe disturbances of their self-identity, memory, and general awareness of themselves and their surroundings may be classified as having these types of disorders, including depersonalization disorder or dissociative identity disorder (which was previously referred to as multiple personality disorder or "split personality").

Cognitive disorder: These affect cognitive abilities, including learning and memory. This category includes delirium and mild and major neurocognitive disorder (previously termed dementia).

Developmental disorder: These disorders initially occur in childhood. Some examples include autism spectrum disorder, oppositional defiant disorder and conduct disorder, and attention deficit hyperactivity disorder (ADHD), which may continue into adulthood. Conduct disorder, if continuing into adulthood, may be diagnosed as antisocial personality disorder (dissocial personality disorder in the ICD). Popular labels such as psychopath (or sociopath) do not appear in the DSM or ICD but are linked by some to these diagnoses.

Somatoform disorders may be diagnosed when there are problems that appear to originate in the body that are thought to be manifestations of a mental disorder. This includes somatization disorder and conversion disorder. There are also disorders of how a person perceives their body, such as body dysmorphic disorder. Neurasthenia is an old diagnosis involving somatic complaints as well as fatigue and low spirits/depression, which is officially recognized by the ICD-10 but no longer by the DSM-IV.

Factitious disorders are diagnosed where symptoms are thought to be reported for personal gain. Symptoms are often deliberately produced or feigned, and may relate to either symptoms in the individual or in someone close to them, particularly people they care for.

There are attempts to introduce a category of relational disorder, where the diagnosis is of a relationship rather than on any one individual in that relationship. The relationship may be between children and their parents, between couples, or others. There already exists, under the category of psychosis, a diagnosis of shared psychotic disorder where two or more individuals share a particular delusion because of their close relationship with each other.

There are a number of uncommon psychiatric syndromes, which are often named after the person who first described them, such as Capgras syndrome, De Clerambault syndrome, Othello syndrome, Ganser syndrome, Cotard delusion, and Ekbom syndrome, and additional disorders such as the Couvade syndrome and Geschwind syndrome.

Various new types of mental disorder diagnoses are occasionally proposed. Among those controversially considered by the official committees of the diagnostic manuals include self-defeating personality disorder, sadistic personality disorder, passive-aggressive personality disorder, gender dysphoria and premenstrual dysphoric disorder.

Signs and symptoms

Course

The onset of psychiatric disorders usually occurs from childhood to early adulthood. Impulse-control disorders and a few anxiety disorders tend to appear in childhood. Some other anxiety disorders, substance disorders and mood disorders emerge later in the mid-teens. Symptoms of schizophrenia typically manifest from late adolescence to early twenties.

The likely course and outcome of mental disorders vary and are dependent on numerous factors related to the disorder itself, the individual as a whole, and the social environment. Some disorders may last a brief period of time, while others may be long-term in nature.

All disorders can have a varied course. Long-term international studies of schizophrenia have found that over a half of individuals recover in terms of symptoms, and around a fifth to a third in terms of symptoms and functioning, with many requiring no medication. While some have serious difficulties and support needs for many years, "late" recovery is still plausible. The World Health Organization concluded that the long-term studies' findings converged with others in "relieving patients, carers and clinicians of the chronicity paradigm which dominated thinking throughout much of the 20th century."

A follow-up study by Tohen and coworkers revealed that around half of people initially diagnosed with bipolar disorder achieve symptomatic recovery (no longer meeting criteria for the diagnosis) within six weeks, and nearly all achieve it within two years, with nearly half regaining their prior occupational and residential status in that period. Less than half go on to experience a new episode of mania or major depression within the next two years.

Disability

Disorder Disability-adjusted life years
Major depressive disorder 65.5 million
Alcohol-use disorder 23.7 million
Schizophrenia 16.8 million
Bipolar disorder 14.4 million
Other drug-use disorders 8.4 million
Panic disorder 7.0 million
Obsessive-compulsive disorder 5.1 million
Primary insomnia 3.6 million
Post-traumatic stress disorder 3.5 million

Some disorders may be very limited in their functional effects, while others may involve substantial disability and support needs. The degree of ability or disability may vary over time and across different life domains. Furthermore, continued disability has been linked to institutionalization, discrimination and social exclusion as well as to the inherent effects of disorders. Alternatively, functioning may be affected by the stress of having to hide a condition in work or school, etc., by adverse effects of medications or other substances, or by mismatches between illness-related variations and demands for regularity.

It is also the case that, while often being characterized in purely negative terms, some mental traits or states labeled as disorders can also involve above-average creativity, non-conformity, goal-striving, meticulousness, or empathy. In addition, the public perception of the level of disability associated with mental disorders can change.

Nevertheless, internationally, people report equal or greater disability from commonly occurring mental conditions than from commonly occurring physical conditions, particularly in their social roles and personal relationships. The proportion with access to professional help for mental disorders is far lower, however, even among those assessed as having a severely disabling condition. Disability in this context may or may not involve such things as:

  • Basic activities of daily living. Including looking after the self (health care, grooming, dressing, shopping, cooking etc.) or looking after accommodation (chores, DIY tasks, etc.)
  • Interpersonal relationships. Including communication skills, ability to form relationships and sustain them, ability to leave the home or mix in crowds or particular settings
  • Occupational functioning. Ability to acquire an employment and hold it, cognitive and social skills required for the job, dealing with workplace culture, or studying as a student.

In terms of total disability-adjusted life years (DALYs), which is an estimate of how many years of life are lost due to premature death or to being in a state of poor health and disability, mental disorders rank amongst the most disabling conditions. Unipolar (also known as Major) depressive disorder is the third leading cause of disability worldwide, of any condition mental or physical, accounting for 65.5 million years lost. The first systematic description of global disability arising in youth, in 2011, found that among 10- to 24-year-olds nearly half of all disability (current and as estimated to continue) was due to mental and neurological conditions, including substance use disorders and conditions involving self-harm. Second to this were accidental injuries (mainly traffic collisions) accounting for 12 percent of disability, followed by communicable diseases at 10 percent. The disorders associated with most disabilities in high-income countries were unipolar major depression (20%) and alcohol use disorder (11%). In the eastern Mediterranean region, it was unipolar major depression (12%) and schizophrenia (7%), and in Africa it was unipolar major depression (7%) and bipolar disorder (5%).

Suicide, which is often attributed to some underlying mental disorder, is a leading cause of death among teenagers and adults under 35. There are an estimated 10 to 20 million non-fatal attempted suicides every year worldwide.

Risk factors

The predominant view as of 2018 is that genetic, psychological, and environmental factors all contribute to the development or progression of mental disorders. Different risk factors may be present at different ages, with risk occurring as early as during prenatal period.

Genetics

A number of psychiatric disorders are linked to a family history (including depression, narcissistic personality disorder and anxiety). Twin studies have also revealed a very high heritability for many mental disorders (especially autism and schizophrenia). Although researchers have been looking for decades for clear linkages between genetics and mental disorders, that work has not yielded specific genetic biomarkers yet that might lead to better diagnosis and better treatments.

Statistical research looking at eleven disorders found widespread assortative mating between people with mental illness. That means that individuals with one of these disorders were two to three times more likely than the general population to have a partner with a mental disorder. Sometimes people seemed to have preferred partners with the same mental illness. Thus, people with schizophrenia or ADHD are seven times more likely to have affected partners with the same disorder. This is even more pronounced for people with Autism spectrum disorders who are 10 times more likely to have a spouse with the same disorder.

Environment