A person who suffers from a major depressive disorder (sometimes also referred to as clinical depression or simply depression) must either have a depressed mood or a loss of interest or pleasure in daily activities consistently for at least a 2 week period. This mood must represent a change from the person’s normal mood. Social, occupational, educational or other important functioning must also be negatively impaired by the change in mood. For instance, a person who has missed work or school because of their depression, or has stopped attending classes altogether or attending usual social engagements.

A depressed mood caused by substances (such as drugs, alcohol, medications) is not considered a major depressive disorder, nor is one which is caused by a general medical condition. Major depressive disorder generally cannot be diagnosed if a person has a history of manic, hypomanic, or mixed episodes (e.g., a bipolar disorder) or if the depressed mood is better accounted for by schizoaffective disorder and is not superimposed on schizophrenia, a delusion or psychotic disorder.

Clinical depression is characterized by the presence of 5 or more of these depressive symptoms:

  • Depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feeling sad, blue, “down in the dumps,” or empty) or observation made by others (e.g., appears tearful or about to cry). (In children and adolescents, this may present as an irritable or cranky, rather than sad, mood.)
  • Markedly diminished interest or pleasure in all, or almost all, activities every day, such as no interest in hobbies, sports, or other things the person used to enjoy doing.
  • Significant weight loss when not dieting or weight gain (e.g., a change of more than 5 percent of body weight in a month), or decrease or increase in appetite nearly every day.
  • Insomnia (inability to get to sleep or difficulty staying asleep) or hypersomnia (sleeping too much) nearly every day
  • Psychomotor agitation (e.g., restlessness, inability to sit still, pacing, pulling at clothes or clothes) or retardation (e.g., slowed speech, movements, quiet talking) nearly every day
  • Fatigue, tiredness, or loss of energy nearly every day (e.g., even the smallest tasks, like dressing or washing, seem difficult to do and take longer than usual).
  • Feelings of worthlessness or excessive or inappropriate guilt nearly every day (e.g., ruminating over minor past failings).
  • Diminished ability to think or concentrate, or indecisiveness, nearly every day (e.g. appears easily distracted, complains of memory difficulties).
  • Recurrent thoughts of death (not just fear of dying), recurrent suicidal ideas without a specific plan, or a suicide attempt or a specific plan for committing suicide

Related: Teen Depression Symptoms

In keeping with updates to the major depressive disorder criteria in DSM-5, a person can suffer from a major depressive episode during a period of Bereavement, i.e., after the loss of a loved one. This is a significant change from the previous DSM-IV criteria, which did not give the diagnosis of major depression if the person was grieving over a significant loss in their lives. This change was made with the rationale that since bereavement may induce great suffering in a person, it may induce an episode of major depressive disorder.

In other words, it is not normal for the symptoms of bereavement to induce marked functional impairment, morbid preoccupation with worthlessness, suicidal ideation, psychotic symptoms, or psychomotor retardation for two months or more. Thus, when they do occur together, the depressive symptoms and functional impairment tend to be more severe and the prognosis is worse compared with bereavement that is not accompanied by major depressive disorder. Bereavement-related depression tends to occur in persons with other vulnerabilities to depressive disorders, and recovery may be facilitated by antidepressant treatment.

 

This criteria has been adapted for DSM-5.