Table 1.

DSM-V classification of depressive disorders⁹

- Major depressive disorder (MDD): a clinical syndrome lasting at least 2 weeks, where patients experience either depressed mood or anhedonia, and at least 4 other symptoms of depression.a Symptoms need to cause significant distress and impairment in one’s life, and cannot be caused by substance abuse or another psychological or medical condition including mania.

- Persistent depressive disorder (PDD): depressed mood that occurs most days for at least 2 years, and the presence of at least 2 of the following 6 symptoms: change in appetite, insomnia or hypersomnia, fatigue, low energy, poor concentration or difficulty making decisions, and feelings of hopelessness. These symptoms may not be caused by substance abuse or a general medical condition, and must cause significant distress or impairment in one’s life. Previously known as dysthymia.

- Depressive disorder NOS: any depressive disorder that does not meet criteria for a specific depressive disorder like PDD or MDD. Depressive disorder NOS was previously broken up into distinct depressive disorders including minor depressive disorder.

- Minor depression: no longer a diagnostic classification and now classified as depressive disorder NOS in DSM-V. Previously defined as a clinical syndrome of depressed mood that lasted at least 2 weeks with at least 2 but fewer than 5 of the symptoms required to diagnose MDD

DSM-V, Diagnostic and Statistical Manual of Mental Disorders, 5^th edition; NOS: not otherwise specified.

^aSymptoms of depression include weight loss, insomnia or hypersomnia, psychomotor agitation or retardation, fatigue, feelings of worthlessness or guilt, diminished ability to think, concentrate, or make decisions, and recurrent suicidal ideation.