Version July 2025
| Possible meanings of the word depression | ||
| Construct | Term | Definition |
| Mood state | Depressed mood | As a mood state, depression consists of feelings of sadness, despair, anxiety, emptiness, discouragement, or hopelessness; appearing tearful; or even having no feelings. Depressed (dysphoric) mood may be a normal and, at times, adaptive response to loss, disappointment, or perceived failure. Alternatively, depressed mood may be a symptom of a psychiatric or general medical disorder. |
| Syndrome | Depression Depressive episode | As a syndrome, depression describes a specific constellation of symptoms and signs. A major depressive episode is a depressive syndrome that can occur in several psychiatric disorders, such as major depressive disorder, bipolar disorder, and schizophrenia. |
| Psychiatric disorder | Depressive disorder | As a psychiatric disorder, depression refers to a diagnosis that meets a specific set of diagnostic criteria. Common depressive disorders include major depressive disorder, persistent depressive disorder, and premenstrual dysphoric disorder. |
| Depressive episode versus disorder | ||
| Major depressive episode | A period lasting at least 2 consecutive weeks, with 5 or more of the following symptoms: depressed mood, anhedonia, insomnia or hypersomnia, change in appetite or weight, psychomotor retardation or agitation, low energy, poor concentration, thoughts of worthlessness or guilt, and recurrent thoughts about death or suicide. At least 1 of the symptoms must be depressed mood or anhedonia. | |
| Major depressive disorder or Major depression | A disorder consisting of at least 1 major depressive episode and no history of mania or hypomania. | |
