DSM-IV criteria for major depressive episode
| A | Five (or more) of the following symptoms have been present during the same two week period and represent a change from previous functioning. At least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure |
| 1 | Depressed mood most of the day, nearly every day, as indicated by either subjective report or observation made by others |
| 2 | Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day |
| 3 | Significant weight loss when not dieting or weight gain, or decrease or increase in appetite, nearly every day |
| 4 | Early insomnia or hypersomnia, nearly every day |
| 5 | Psychomotor agitation, nearly every day |
| 6 | Feelings of worthlessness or excessive or inappropriate guilt, nearly every day |
| 7 | Diminished ability to think or concentrate, or indecisiveness, nearly every day |
| 8 | Recurrent thought of death, recurrent suicidal ideation without a specific plan, or a suicide attempt or specific plan for committing suicide |