Depression subtyping: treatment implications.

The complexity of subtyping depression and the implications that such subtyping has on treatment choices are discussed in this article. The most recent edition of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) directs clinicians to classify the mood disorders in depressed patients as unipolar, bipolar, due to a general medical condition, or due to substance abuse. The focus of this article is unipolar (major depression and dysthymia) and bipolar I and II disorders with and without feature specifiers for atypical depression, seasonal affective disorder, psychotic depression, and postpartum depression. Anxious depression, which is not a DSM-IV classification, is also reviewed.