Major Depressive Disorder

DSM-5 Diagnostic Criteria

The DSM-5 outlines the following criterion to make a diagnosis of depression. The individual must be experiencing five or more symptoms during the same 2-week period and at least one of the symptoms should be either (1) depressed mood or (2) loss of interest or pleasure.

• Depressed mood most of the day, nearly every day.
  • As indicated by either subjective report (e.g., feels sad, empty, hopeless) or observation made by others (e.g.,appears tearful). (Note: In children and adolescents, can be irritable mood.)
• Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day.
• Significant weight loss when not dieting or weight gain, or decrease or increase in appetite nearly every day.
• Insomnia or hypersomnia nearly every day.
• A slowing down of thought and a reduction of physical movement (observable by others, not merely subjective feelings of restlessness or being slowed down).
• Fatigue or loss of energy nearly every day.
• Feelings of worthlessness or excessive or inappropriate guilt nearly every day.
• Diminished ability to think or concentrate, or indecisiveness, nearly every day.
• Recurrent thoughts of death, recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide.

To receive a diagnosis of depression, these symptoms must cause the individual clinically significant distress or impairment in social, occupational, or other important areas of functioning. The symptoms must also not be a result of substance abuse or another medical condition.

Research

• Anhedonia (inability to engage in physical activities) has less functional impairment than avoidance of tasks that require high cognitive load.

• The ability to control intrusive memories and thoughts is weakened by sleep disturbance and sleep deprivation.