The significance of subsyndromal depression in geriatrics.

Clinically significant non-major depression has been underinvestigated, despite its high prevalence and public health impact. Although there is increasing recognition of the importance of subsyndromal forms of depression, their nosologic boundaries and neurobiologic mechanisms remain largely unknown. This review discusses the literature pertaining to the current concepts, phenomenology, neurobiology, and treatment approaches for geriatric non-major clinically significant depression. The authors examine the similarities and differences between various subtypes of depressive disorders, and compare non-major clinically significant depression in the elderly with non-geriatric adult populations. The authors draw conclusions from the published literature and present clinical criteria for the diagnosis of clinically significant non-major depression in the elderly.