Major depressive episode | |
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Specialty | Psychiatry |
A major depressive episode (MDE) is a period characterized by the symptoms of major depressive disorder. Sufferers primarily have a depressed mood
for two weeks or more, and a loss of interest or pleasure in everyday
activities, accompanied by other symptoms such as feelings of emptiness,
hopelessness, anxiety,
worthlessness, guilt and irritability, changes in appetite, problems
concentrating, remembering details or making decisions, and thoughts of
suicide. Insomnia or hypersomnia, aches, pains, or digestive problems that are resistant to treatment may also be present. The description has been formalized in psychiatric diagnostic criteria such as the DSM-5 and ICD-10.
Biological, psychological, and social factors are believed to be
involved in the cause of depression, although it is still not well
understood.
Factors like socioeconomic status, life experience, and personality
tendencies play a role in the development of depression and may
represent increases in risk for developing a major depressive episode. There are many theories as to how depression occurs. One interpretation is that neurotransmitters
in the brain are out of balance, and this results in feelings of
worthlessness and despair. Magnetic resonance imaging shows that brains
of people who have depression look different than the brains of people
not exhibiting signs of depression. A family history of depression increases the chance of being diagnosed.
Emotional pain and economic costs are associated with depression.
In the United States and Canada, the costs associated with major
depression are comparable to those related to heart disease, diabetes, and back problems and are greater than the costs of hypertension. According to the Nordic Journal of Psychiatry, there is a direct correlation between major depressive episode and unemployment.
Treatments for a major depressive episode include psychotherapy and antidepressants, although in more serious cases, hospitalization or intensive outpatient treatment may be required.
Signs and symptoms
The criteria below are based on the formal DSM-V
criteria for a major depressive episode. A diagnosis of major
depressive episode requires that the patient has experienced five or
more of the symptoms
below, and one of the symptoms must be either depressed mood or loss of
interest or pleasure (although both are frequently present). These symptoms must be present for at least 2 weeks and represent a change from the patient's normal behavior.
Depressed mood and loss of interest (anhedonia)
Either depressed mood or a loss of interest or pleasure must be present for the diagnosis of a major depressive episode. Depressed mood is the most common symptom seen in major depressive episodes. Interest or pleasure in everyday activities can be decreased; this is referred to as anhedonia.
These feelings must be present on an everyday basis for two weeks or
longer to meet DSM-V criteria for a major depressive episode.
In addition, the person may experience one or more of the following
emotions: sadness, emptiness, hopelessness, indifference, anxiety,
tearfulness, pessimism, emotional numbness, or irritability. In children and adolescents, a depressed mood often appears more irritable in nature. There may be a loss of interest in or desire for sex, or other activities once found to be pleasant.
Friends and family of the depressed person may notice that they have
withdrawn from friends, or neglected or quit doing activities that were
once a source of enjoyment.
Sleep
Nearly every day, the person may sleep excessively, known as hypersomnia, or not enough, known as insomnia. Insomnia is the most common type of sleep disturbance for people who are clinically depressed. Symptoms of insomnia include trouble falling asleep, trouble staying asleep, or waking up too early in the morning.
Hypersomnia is a less common type of sleep disturbance. It may include
sleeping for prolonged periods at night or increased sleeping during the
daytime.
The sleep may not be restful, and the person may feel sluggish despite
many hours of sleep, which may amplify their depressive symptoms and
interfere with other aspects of their lives. Hypersomnia is often associated with an atypical depression, as well as seasonal affective disorder.
Feelings of guilt or worthlessness
Depressed people may have feelings of guilt that go beyond a normal level or are delusional. These feelings of guilt and/or worthlessness are excessive and inappropriate. Major depressive episodes are notable for a significant, often unrealistic, drop in self-esteem.
The guilt and worthlessness experienced in a major depressive episode
can range from subtle feelings of guilt to frank delusions or to shame
and humiliation. Additionally, self-loathing is common in clinical depression, and can lead to a downward spiral when combined with other symptoms.
Loss of energy
Persons going through a major depressive episode often have a general lack of energy, as well as fatigue and tiredness, nearly every day for at least 2 weeks.
A person may feel tired without having engaged in any physical
activity, and day-to-day tasks become increasingly difficult. Job tasks
or housework become very tiring, and the patient finds that their work
begins to suffer.
Decreased concentration
Nearly every day, the person may be indecisive or have trouble thinking or concentrating.
These issues cause significant difficulty in functioning for those
involved in intellectually demanding activities, such as school and
work, especially in difficult fields. Depressed people often describe a slowing of thought, inability to concentrate and make decisions, and being easily distracted. In the elderly, the decreased concentration caused by a major depressive episode may present as deficits in memory. This is referred to as pseudodementia and often goes away with treatment. Decreased concentration may be reported by the patient or observed by others.
Change in eating, appetite, or weight
In
a major depressive episode, appetite is most often decreased, although a
small percentage of people experience an increase in appetite. A person experiencing a depressive episode may have a marked loss or gain of weight (5% of their body weight in one month). A decrease in appetite may result in weight loss that is unintentional or when a person is not dieting.
Some people experience an increase in appetite and may gain significant
amounts of weight. They may crave certain types of food, such as sweets
or carbohydrates. In children, failure to make expected weight gains may be counted towards this criteria. Overeating is often associated with atypical depression.
Motor activity
Nearly every day, others may see that the person's activity level is not normal. People suffering from depression may be overly active (psychomotor agitation) or be very lethargic (psychomotor retardation).
Psychomotor agitation is marked by an increase in body activity which
may result in restlessness, an inability to sit still, pacing, hand
wringing, or fidgeting with clothes or objects. Psychomotor retardation results in a decrease in body activity or thinking. In this case, a depressed person may demonstrate a slowing of thinking, speaking, or body movement.
They may speak more softly or say less than usual. To meet diagnostic
criteria, changes in motor activity must be so abnormal that it can be
observed by others. Personal reports of feeling restless or feeling slow do not count towards the diagnostic criteria.
Thoughts of death and suicide
A person going through a major depressive episode may have repeated thoughts about death (other than the fear of dying) or suicide (with or without a plan), or may have made a suicide attempt.
The frequency and intensity of thoughts about suicide can range from
believing that friends and family would be better off if one were dead,
to frequent thoughts about committing suicide (generally related to
wishing to stop the emotional pain), to detailed plans about how the
suicide would be carried out. Those who are more severely suicidal may have made specific plans and decided upon a day and location for the suicide attempt.
Causes
The cause of a major depressive episode is not well understood. However, the mechanism is believed to be a combination of biological, psychological, and social factors. A major depressive episode can often follow an acute stress in someone's life.
Evidence suggests that psychosocial stressors play a larger role in the
first 1-2 depressive episodes, while having less influence in later
episodes. People who experience a major depressive episode often have other mental health issues.
Other risk factors for a depressive episode include:
- Family history of a mood disorder
- Recent negative life events
- Personality (insecure, worried, stress-sensitive, obsessive, unassertive, dependent)
- Early childhood trauma
- Postpartum
- Lack of interpersonal relationships
One gene by itself has not been linked to depression. Studies show
that depression can be passed down in families, but this is believed to
be due to a combined effect of genetic and environmental factors. Other medical conditions, like hypothyroidism for example, may cause someone to experience similar symptoms as a major depressive episode, however this would be considered a mood disorder due to a general medical condition, according to the DSM-V.
Diagnosis
Screening
Healthcare
providers may screen patients in the general population for depression
using a screening tool, such as the Patient Healthcare Questionnaire-2
(PHQ-2). If the PHQ-2 screening is positive for depression, a provider may then administer the PHQ-9. The Geriatric Depression Scale is a screening tool that can be used in the elderly population.
Criteria
The two main symptoms in a major depressive episode are a depressed mood or a loss of interest or pleasure. From the list below, one bold symptom
and four other symptoms must be present for a diagnosis of major
depressive episode. These symptoms must be present for at least 2 weeks
and must be causing significant distress or impairment in functioning.
- Depressed mood
- Loss of interest or pleasure
- Change in appetite
- Change in sleep
- Change in body activity (psychomotor changes)
- Loss of energy
- Feelings of worthlessness and excessive or inappropriate guilt
- Indecisiveness or a decrease in concentration
- Suicidal ideation
To diagnose a major depressive episode, a trained healthcare provider must make sure that:
- The symptoms do not meet the criteria for a mixed episode.
- The symptoms must cause considerable distress or impair functioning at work, in social settings or in other important areas in order to qualify as an episode.
- The symptoms are not due to the direct physiological effects of a substance (e.g., abuse of a drug or medication) or a general medical condition (e.g., hypothyroidism).
Workup
No labs are diagnostic of a depressive episode.
But some labs can help rule out general medical conditions that may
mimic the symptoms of a depressive episode. Healthcare providers may
order some routine blood work, including routine blood chemistry, CBC
with differential, thyroid function studies, and Vitamin B12 levels, before making a diagnosis.
Differential Diagnosis
There are other mental health disorders or medical conditions to consider before diagnosing a major depressive episode:
- Bipolar disorder
- Cyclothymic disorder
- Disruptive mood dysregulation disorder
- Persistent depressive disorder
- Anxiety disorder (Generalized anxiety, PTSD, obsessive compulsive disorder)
- Substance abuse or Substance Use Disorder
- Personality disorder with depressive symptoms
- Adjustment disorder
- Depression due to a general medical condition
- Premenstrual dysphoric disorder
Treatment
Depression
is a treatable illness. Treatments for a major depressive episode may
be provided by mental health specialists (i.e. psychologist,
psychiatrists, social workers, counselors, etc.), mental health centers
or organizations, hospitals, outpatient clinics, social service
agencies, private clinics, peer support groups, clergy, and employee
assistance programs. The treatment plan could include psychotherapy alone, antidepressant medications alone, or a combination of medication and psychotherapy.
For major depressive episodes of severe intensity (multiple
symptoms, minimal mood reactivity, severe functional impairment),
combined psychotherapy and antidepressant medications are more effective
than psychotherapy alone.
Meta-analyses suggest that the combination of psychotherapy and
antidepressant medications is more effective in treating mild and
moderate forms of depression as well, compared to either type of
treatment alone. Patients with severe symptoms may require outpatient treatment or hospitalization.
The treatment of a major depressive episode can be split into 3 phases:
- Acute phase: the goal of this phase is to resolve the current major depressive episode
- Continuation: this phase continues the same treatment from the acute phase for 4–8 months after the depressive episode has resolved and the goal is to prevent relapse
- Maintenance: this phase is not necessary for every patient but is often used for patients who have experienced 2-3 or more major depressive episodes. Treatment may be maintained indefinitely to prevent the occurrence and severity of future episodes.
Therapy
Psychotherapy,
also known as talk therapy, counseling, or psychosocial therapy, is
characterized by a patient talking about their condition and mental
health issues with a trained therapist. Different types of psychotherapy
are used as a treatment for depression. These include cognitive behavioral therapy, interpersonal therapy, dialectical behavior therapy, acceptance and commitment therapy, and mindfulness techniques.
Evidence shows that cognitive behavioral therapy can be as effective as
medication in the treatment of a major depressive episode.
Psychotherapy may be the first treatment used for mild to
moderate depression, especially when psychosocial stressors are playing a
large role. Psychotherapy alone may not be as effective for more severe forms of depression.
Some of the main forms of psychotherapies used for treatment of a
major depressive episode along with what makes them unique are included
below:
- Cognitive psychotherapy: focus on patterns of thinking
- Interpersonal psychotherapy: focus on relationships, losses, and conflict resolution
- Problem-solving psychotherapy: focus on situations and strategies for problem-solving
- Psychodynamic psychotherapy: focus on defense mechanisms and coping strategies
Medication
Medications used to treat depression include selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), norepinephrine-dopamine reuptake inhibitors (NDRIs), tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs), and atypical antidepressants such as mirtazapine, which do not fit neatly into any of the other categories.
Different antidepressants work better for different individuals. It is
often necessary to try several before finding one that works best for a
specific patient. Some people may find it necessary to combine
medications, which could mean two antidepressants or an antipsychotic
medication in addition to an antidepressant. If a person's close relative has responded well to a certain medication, that treatment will likely work well for him or her. Antidepressant medications are effective in the acute, continuation, and maintenance phases of treatment, as described above.
The treatment benefits of antidepressant medications are often
not seen until 1–2 weeks into treatment, with maximum benefits being
reached around 4–6 weeks.
Most healthcare providers will monitor patients more closely during the
acute phase of treatment and continue to monitor at longer intervals in
the continuation and maintenance phases.
Sometimes, people stop taking antidepressant medications due to
side effects, although side effects often become less severe over time. Suddenly stopping treatment or missing several doses may cause withdrawal-like symptoms.
Some studies have shown that antidepressants may increase short-term
suicidal thoughts or actions, especially in children, adolescents, and
young adults. However, antidepressants are more likely to reduce a
person's risk of suicide in the long run.
Below are listed the main classes of antidepressant medications,
some of the most common drugs in each category, and their major side
effects:
- Selective serotonin reuptake inhibitors (citalopram, escitalopram, paroxetine, fluoxetine, sertraline): major side effects include nausea, diarrhea, and sexual dysfunction
- Serotinin and norepinephrine reuptake inhibitors (duloxetine, venlafaxine, desvenlafaxine): major side effects include nausea, diarrhea, increased heart rate, increased blood pressure, and tremor
- Tricyclic antidepressants (amitryptiline, desipramine, doxepin, imipramine, nortriptyline): major side effects include sedation, low blood pressure when moving from sitting to standing (orthostatic hypotension), tremor, and heart issues like conduction delays or arrythmias
- Monoamine oxidase inhibitors (isocarboxazid, phenelzine, selegiline): major side effects include high blood pressure (emergency) if eaten with foods rich in tyramine (e.g. cheeses, some meats, and home-brewed beer), sedation, tremor, and orthostatic hypotension
Alternative treatments
There
are several treatment options that exist for people who have
experienced several episodes of major depression or have not responded
to several treatments.
Electroconvulsive therapy is a treatment in which a generalized seizure is induced by means of electrical current. The mechanism of action of the treatment is not clearly understood but has been show to be most effective in the most severely depressed patients.
For this reason, electroconvulsive therapy is preferred for the most
severe forms of depression or depression that has not responded to other
treatments, known as refractory depression.
Vagus nerve stimulation
is another alternative treatment that has been proven to be effective
in the treatment of depression, especially people that have been
resistant to four or more treatments. Some of the unique benefits of vagus nerve stimulation include improved neurocognitive function and a sustained clinical response.
Transcranial magnetic stimulation is also an alternative treatment for a major depressive episode.
It is a noninvasive treatment that is easily tolerated and shows an
antidepressant effect, especially in more typical depression and younger
adults.
Prognosis
If
left untreated, a typical major depressive episode may last for about
six months. About 20% of these episodes can last two years or more.
About half of depressive episodes end spontaneously.
However, even after the major depressive episode is over, 20% to 30% of
patients have residual symptoms, which can be distressing and
associated with disability. Fifty percent of people will have another major depressive episode after the first. However, the risk of relapse is decreased by taking antidepressant medications for more than 6 months.
Symptoms completely improve in six to eight weeks in sixty to seventy percent of patients.
The combination of therapy and antidepressant medications has been
shown to improve resolution of symptoms and outcomes of treatment.
Suicide is the 8th leading cause of death in the United States.
The risk of suicide is increased during a major depressive episode.
However, the risk is even more elevated during the first two phases of
treatment. There are several factors associated with an increased risk of suicide, listed below:
- Greater than 45 years of age
- Caucasian
- Male
- History of suicide attempt or self-injurious behaviors
- Family history of suicide or mental illness
- Recent severe loss
- Poor health
- Detailed plan
- Inability to accept help
- Lack of social support
- Psychotic features (auditory or visual hallucinations, disorganization of speech, behavior, or thought)
- Alcohol or drug use or comorbid psychiatric disorder
- Severe depression
Epidemiology
Estimates of the numbers of people suffering from major depressive episodes and major depressive disorder
(MDD) vary significantly. Overall, 13-20% of people will experience
significant depressive symptoms at some point in their life. The overall prevalence of MDD is slightly lower ranging from 3.7-6.7% of people. In their lifetime, 20% to 25% of women, and 7% to 12% of men will suffer a major depressive episode. The peak period of development is between the ages of 25 and 44 years.
Onset of major depressive episodes or MDD often occurs to people in
their mid-20s, and less often to those over 65. The prevalence of
depressive symptoms in the elderly is around 1-2%. Elderly persons in nursing homes may have increased rates, up to 15-25%. African-Americans have higher rates of depressive symptoms compared to other races. Prepubescent girls are affected at a slightly higher rate than prepubescent boys.
In a National Institute of Mental Health study, researchers found that more than 40% of people with post-traumatic stress disorder suffered from depression four months after the traumatic event they experienced.
Women who have recently given birth may be at increased risk for having a major depressive episode. This is referred to as postpartum depression and is a different health condition than the baby blues, a low mood that resolves within 10 days after delivery.
Comorbid disorders
Major depressive episodes may show comorbidity
(association) with other physical and mental health problems. About
20–25% of individuals with a chronic general medical condition will
develop major depression. Common comorbid disorders include: eating disorders, substance-related disorders, panic disorder, and obsessive-compulsive disorder. Up to 25% of people who experience a major depressive episode have a pre-existing dysthymic disorder.
Some persons who have a fatal illness or are at the end of their life may experience depression, although this is not universal.