What are the defining characteristics and symptoms of a major depressive episode?

Major depressive episode, also known as major depression or clinical depression, is a common mental disorder that affects millions of people worldwide. It is characterized by a persistent feeling of sadness, hopelessness, and loss of interest in activities that were once enjoyable. This debilitating condition can significantly impact one’s daily life and relationships, making it crucial to understand its defining characteristics and symptoms. In this article, we will delve into the key characteristics and symptoms of a major depressive episode to gain a better understanding of this mental health disorder.

A major depressive episode is the cluster of symptoms of major depressive disorder. The description has been formalised in psychiatric diagnostic criteria such as the DSM-IV and ICD-10, and is characterized by severe, highly persistent depression, and a loss of interest or pleasure in everyday activities, which is often manifested by lack of appetite, chronic fatigue, and sleep disturbances (somnipathy). The individual may think about suicide, and indeed an increased risk of actual suicide is present.

In addition to the emotional pain endured by those suffering from depression, significant economic costs are associated with depression. In fact, American and Canadian studies have indicated that the costs associated with depression are greater than those associated with hypertension, and equal to those of heart disease, diabetes, and back problems.



The criteria below are based on the formal DSM-IV criteria for a Major Depressive Episode. A diagnoses of major depressive episode requires that the patient has—over a two-week period—experienced five or more of the symptoms below, and these must be outside the patient’s normal behaviour. Either depressed mood or decreased interest or pleasure must be one of the five (although both are frequently concomitant).



  • For the better part of nearly every day, the patient reports a depressed mood or appears depressed to others.
  • The patient may state that he or she has been feeling sad, depressed, blue, empty, “down in the dumps,” hopeless, etc. If the patient is in denial about these feelings, yet appears to be on the verge of tearfulness, manifests a depressed facial expression and disposition, or appears to be overly irritable, these may also indicate the presence of depressed mood. Some people may report physical complaints (i.e., aches, pains, headaches) rather than depressed mood, and physical symptoms without physical cause are sometimes indicators of depression. (See Myalgia and Neuralgia.)


Anhedonia and loss of interest

  • For most of nearly every day, interest or pleasure is markedly decreased in nearly all activities (noted by the patient or by others). (See Anhedonia)
  • People suffering with depression tend to lose interest in things they once found enjoyable. Activities are no longer enjoyable and there is often a loss of interest in or desire for sex. People who are depressed may say, “I just don’t care anymore,” or “nothing matters anymore.” Friends and family of the depressed person may notice that he/she has withdrawn from friends, or has neglected or quit doing activities that were once a source of enjoyment.


Change in eating, appetite, or weight

  • Although not dieting, there is a marked loss or gain of weight (such as 5% in one month) or appetite is markedly decreased or increased nearly every day.
  • Changes in appetite take on two manifestations: under- or over-eating.
  • In the first instance, some people never feel hungry, can go long periods without wanting to eat, may forget to eat, or if they do eat a small amount of food may be sufficient. A reduction in weight is often associated with a melancholic type of depression.
  • In the second instance, some people tend toward an increase in appetite and may gain significant amounts of weight. They may tend to crave certain types of food such as sweets or carbohydrates. People with seasonal affective disorder (SAD) often crave foods high in carbohydrates. Weight gain is often associated with atypical depression.



  • Nearly every day the patient sleeps 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. Waking in the middle of the night and being unable to go back to sleep is known as “middle insomnia”; waking too early as “terminal insomnia”, and; having difficulty falling asleep at night is “initial” insomnia. Insomnia is often associated with a melancholic type of depression.
  • A less frequent sleeping problem is oversleeping (called “hypersomnia”). This may occur in the form of sleeping for prolonged periods at night or increased sleeping during the daytime. Even with excess sleep, a person may still feel tired and sluggish during the day. People with seasonal affective disorder (SAD) may sleep longer during the winter months. Hypersomnia is often associated with an atypical depression.


Motor activity

  • Nearly every day others can see that the patient’s activity is agitated or slow.
  • People suffering from depression may be either quite agitated (psychomotor agitation), or very lethargic (psychomotor retardation) in their mannerisms and behavior. If a person is agitated, he or she may find it difficult to sit still, may pace the room, wring his/her hands, or fidget with clothes or objects. Someone with psychomotor retardation tend to move sluggishly, may move across a room very slowly, avert his/her eyes, sit slumped in a chair and speak slowly, saying little.
  • In terms of diagnosis, the agitation or slowing down of one’s demeanor must be to the degree that it can be observed by others.



  • Nearly every day the person experiences extreme fatigue.
  • A decrease in energy and feeling fatigued are very common symptoms for those who are clinically depressed. A person may feel tired without having engaged in any physical activity, and day-to-day tasks become difficult, including getting washed and dressed in the morning. Job tasks or housework become very tiring, and the person finds that his/her work at home, school, or on the job suffers.



  • Nearly every day the patient feels worthless or inappropriately guilty. These feelings are not just about being depressed, they may be delusional.
  • Depressed people may think of themselves in very negative, unrealistic ways such as manifesting a preoccupation with past “failures”, personalisation of trivial events, or believing that minor mistakes prove their inadequacy. They also may have an unrealistic sense of personal responsibility and see things beyond their control as being their fault. Additionally, self-loathing is common in clinical depression, and can lead to a downward spiral when combined with other symptoms.



  • Noted by the patient or by others, nearly every day the patient is indecisive or has trouble thinking or concentrating.
  • A person with depression frequently experiences negative and pessimistic thoughts, and reports that his/her ability to think, concentrate, or make decisions becomes impaired. Memory and distraction problems are common. This problem can be notably pronounced, causing significant difficulty in functioning for those involved in intellectually demanding activities.


Thoughts of death

  • The patient has had repeated thoughts about death (other than the fear of dying), suicide (with or without a plan) or has 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. Less severely suicidal people may have regular thoughts of suicide, while those who are more severely suicidal may have made specific plans and decided upon a day and location for the suicide attempt.
  • Thoughts of suicide occur mostly when triggered. Thoughts of suicide happen more frequently than normal.


Diagnostic caveats

In diagnosing the symptoms a trained therapist must take the following into account:

  • These symptoms must cause clinically important distress, or impair work, social or personal functioning, and they should not fulfil the criteria for Mixed 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).
  • Other than in the case of severe symptoms (severely impaired functioning, severe preoccupation with worthlessness, ideas of suicide, delusions or hallucinations or psychomotor retardation), the episode should not have begun within two months of the loss of a loved one. (See Bereavement.)



If left untreated, a typical major depressive episode may last for about six months, while about 20% of these episodes can last two years or more, with 50% of depressive episodes ending 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.

Regarding the treatment of major depressive episodes of severe intensity (multiple symptoms, minimal mood reactivity, severe functional impairment), combined psychotherapy plus antidepressant medications are more effective than psychotherapy alone.



Estimates of the numbers of people suffering from major depressive episodes and Major Depressive Disorder (MDD) vary significantly. Between 10% and 25% of women, and between 5% and 12% of men will suffer a major depressive episode.

Fewer people, between 5% and 9% of women and between 2% and 3% of men, will have MDD, or full-blown depression. Depression occurs nearly twice as often in adolescent and adult females as in males, and 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. Prepubescent girls and boys are affected equally. Additionally, socio-economic or environmental factors do not appear to have any bearing on the incidence of a major depressive episode or MDD.

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