The essential feature of a Major Depressive Episode is a period of at least 2 weeks during which there is either depressed mood or the loss of interest or pleasure in nearly all activities. In children and adolescents, the mood may be irritable rather than sad. The individual must also experience at least four additional symptoms drawn from a list that includes changes in appetite or weight, sleep, and psychomotor activity; decreased energy; feelings of worthlessness or guilt; difficulty thinking, concentrating, or making decisions; or recurrent thoughts of death or suicidal ideation, plans, or attempts. To count toward a Major Depressive Episode, a symptom must either be newly present or must have clearly worsened compared with the person’s preepisode status. The symptoms must persist for most of the day, nearly every day, for at least 2 consecutive weeks. The episode must be accompanied by clinically significant distress or impairment in social, occupational, or other important areas of functioning. For some individuals with milder episodes, functioning may appear to be normal but requires markedly increased effort.
The mood in a Major Depressive Episode is often described by the person as depressed, sad, hopeless, discouraged, or “down in the dumps” (Criterion A1). In some cases, sadness may be denied at first, but may subsequently be elicited by interview (e.g., by pointing out that the individual looks as if he or she is about to cry). In some individuals who complain of feeling “blah,” having no feelings, or feeling anxious, the presence of a depressed mood can be inferred from the person’s facial expression and demeanor. Some individuals emphasize somatic complaints (e.g., bodily aches and pains) rather than reporting feelings of sadness. Many individuals report or exhibit increased irritability (e.g., persistent anger, a tendency to respond to events with angry outbursts or blaming others, or an exaggerated sense of frustration over minor matters). In children and adolescents, an irritable or cranky mood may develop rather than a sad or dejected mood. This presentation should be differentiated from a “spoiled child” pattern of irritability when frustrated.
Loss of interest or pleasure is nearly always present, at least to some degree. Individuals may report feeling less interested in hobbies, “not caring anymore,” or not feeling any enjoyment in activities that were previously considered pleasurable (Criterion A2). Family members often notice social withdrawal or neglect of pleasurable avocations (e.g., a formerly avid golfer no longer plays, a child who used to enjoy soccer finds excuses not to practice). In some individuals, there is a significant reduction from previous levels of sexual interest or desire.
Appetite is usually reduced, and many individuals feel that they have to force themselves to eat. Other individuals, particularly those encountered in ambulatory settings, may have increased appetite and may crave specific foods (e.g., sweets or other carbohydrates). When appetite changes are severe (in either direction), there may be a significant loss or gain in weight, or, in children, a failure to make expected weight gains may be noted (Criterion A3).
The most common sleep disturbance associated with a Major Depressive Episode is insomnia (Criterion A4). Individuals typically have middle insomnia (i.e., waking up during the night and having difficulty returning to sleep) or terminal insomnia (i.e., waking too early and being unable to return to sleep). Initial insomnia (i.e., difficulty falling asleep) may also occur. Less frequently, individuals present with oversleeping (hypersomnia) in the form of prolonged sleep episodes at night or increased daytime sleep. Sometimes the reason that the individual seeks treatment is for the disturbed sleep.
Psychomotor changes include agitation (e.g., the inability to sit still, pacing, hand-wringing; or pulling or rubbing of the skin, clothing, or other objects) or retardation (e.g., slowed speech, thinking, and body movements; increased pauses before answering; speech that is decreased in volume, inflection, amount, or variety of content, or muteness) (Criterion A5). The psychomotor agitation or retardation must be severe enough to be observable by others and not represent merely subjective feelings.
Decreased energy, tiredness, and fatigue are common (Criterion A6). A person may report sustained fatigue without physical exertion. Even the smallest tasks seem to require substantial effort. The efficiency with which tasks are accomplished may be reduced. For example, an individual may complain that washing and dressing in the morning are exhausting and take twice as long as usual.
The sense of worthlessness or guilt associated with a Major Depressive Episode may include unrealistic negative evaluations of one’s worth or guilty preoccupations or ruminations over minor past failings (Criterion A7). Such individuals often misinterpret neutral or trivial day-to-day events as evidence of personal defects and have an exaggerated sense of responsibility for untoward events. For example, a realtor may become preoccupied with self-blame for failing to make sales even when the market has collapsed generally and other realtors are equally unable to make sales. The sense of worthlessness or guilt may be of delusional proportions (e.g., an individual who is convinced that he or she is personally responsible for world poverty). Blaming oneself for being sick and for failing to meet occupational or interpersonal responsibilities as a result of the depression is very common and, unless delusional, is not considered sufficient to meet this criterion.
Many individuals report impaired ability to think, concentrate, or make decisions (Criterion A8). They may appear easily distracted or complain of memory difficulties. Those in intellectually demanding academic or occupational pursuits are often unable to function adequately even when they have mild concentration problems (e.g., a computer programmer who can no longer perform complicated but previously manageable tasks). In children, a precipitous drop in grades may reflect poor concentration. In elderly individuals with a Major Depressive Episode, memory difficulties may be the chief complaint and may be mistaken for early signs of a dementia (“pseudodementia”). When the Major Depressive Episode is successfully treated, the memory problems often fully abate. However, in some individuals, particularly elderly persons, a Major Depressive Episode may sometimes be the initial presentation of an irreversible dementia.
Frequently there may be thoughts of death, suicidal ideation, or suicide attempts (Criterion A9). These thoughts range from a belief that others would be better off if the person were dead, to transient but recurrent thoughts of committing suicide, to actual specific plans of how to commit suicide. The frequency, intensity, and lethality of these thoughts can be quite variable. Less severely suicidal individuals may report transient (1- to 2-minute), recurrent (once or twice a week) thoughts. More severely suicidal individuals may have acquired materials (e.g., a rope or a gun) to be used in the suicide attempt and may have established a location and time when they will be isolated from others so that they can accomplish the suicide. Although these behaviors are associated statistically with suicide attempts and may be helpful in identifying a high-risk group, many studies have shown that it is not possible to predict accurately whether or when a particular individual with depression will attempt suicide. Motivations for suicide may include a desire to give up in the face of perceived insurmountable obstacles or an intense wish to end an excruciatingly painful emotional state that is perceived by the person to be without end.
A diagnosis of a Major Depressive Episode is not made if the symptoms meet criteria for a Mixed Episode (Criterion B). A Mixed Episode is characterized by the symptoms of both a Manic Episode and a Major Depressive Episode occurring nearly every day for at least a 1-week period.
The degree of impairment associated with a Major Depressive Episode varies, but even in mild cases, there must be either clinically significant distress or some interference in social, occupational, or other important areas of functioning (Criterion C). If impairment is severe, the person may lose the ability to function socially or occupationally. In extreme cases, the person may be unable to perform minimal self-care (e.g., feeding or clothing self) or to maintain minimal personal hygiene.
A careful interview is essential to elicit symptoms of a Major Depressive Episode. Reporting may be compromised by difficulties in concentrating, impaired memory, or a tendency to deny, discount, or explain away symptoms. Information from additional informants can be especially helpful in clarifying the course of current or prior Major Depressive Episodes and in assessing whether there have been any Manic or Hypomanic Episodes. Because Major Depressive Episodes can begin gradually, a review of clinical information that focuses on the worst part of the current episode may be most likely to detect the presence of symptoms. The evaluation of the symptoms of a Major Depressive Episode is especially difficult when they occur in an individual who also has a general medical condition (e.g., cancer, stroke, myocardial infarction, diabetes). Some of the criterion items of a Major Depressive Episode are identical to the characteristic signs and symptoms of general medical conditions (e.g., weight loss with untreated diabetes, fatigue with cancer). Such symptoms should count toward a Major Depressive Episode except when they are clearly and fully accounted for by a general medical condition. For example, weight loss in a person with ulcerative colitis who has many bowel movements and little food intake should not be counted toward a Major Depressive Episode. On the other hand, when sadness, guilt, insomnia, or weight loss are present in a person with a recent myocardial infarction, each symptom would count toward a Major Depressive Episode because these are not clearly and fully accounted for by the physiological effects of a myocardial infarction. Similarly, when symptoms are clearly due to mood-incongruent delusions or hallucinations (e.g., a 30-pound weight loss related to not eating because of a delusion that one’s food is being poisoned), these symptoms do not count toward a Major Depressive Episode.
By definition, a Major Depressive Episode is not due to the direct physiological effects of a drug of abuse (e.g., in the context of Alcohol Intoxication or Cocaine Withdrawal), to the side effects of medications or treatments (e.g., steroids), or to toxin exposure. Similarly, the episode is not due to the direct physiological effects of a general medical condition (e.g., hypothyroidism) (Criterion D). Moreover, if the symptoms begin within 2 months of the loss of a loved one and do not persist beyond these 2 months, they are generally considered to result from Bereavement, unless they are associated with marked functional impairment or include morbid preoccupation with worthlessness, suicidal ideation, psychotic symptoms, or psychomotor retardation (Criterion E).