Mood Disorders
The Diagnostic and Statistical Manual of Mental Disorders, Version 4 (DSM-IV), is the official guidebook for classification of psychiatric disorders. The DSM-IV currently presents under the broad heading of Mood Disorders those disorders that have as their central feature a disturbance in mood.
Major depression is characterized by one or more major depressive episodes, which are defined as experiencing two or more weeks of (1) depressed mood and/or (2) loss of interest or pleasure in daily activities. To be diagnosed with major depression, a person must experience one or both of these symptoms and a total of five or more depressive symptoms. For more information, see Major Depression.
Mild-to-moderate depression is called dysthymia, which involves depressed mood for a protracted period of time—at least two years—but without major depressive episodes. To be diagnosed with mild-to-moderate depression, a person must exhibit depressed mood plus at least two other mood-related symptoms. For more information, see Mild-to-Moderate Depression.
Bipolar disorder (manic depression) is cyclical. Unlike depression, which is characterized only by lows and is therefore sometimes called unipolar depression, bipolar disorder involves mood swings from very low (depression) to inappropriately high (mania). Three types of bipolar disorder are distinguished. Bipolar I disorder involves the most radical mood swings—from major depression to extreme mania. Bipolar II disorder involves deep lows (major depression) cycling with moderate mania (hypomania). Cyclothymia is a cycling mood disorder characterized by mood alternating between mild-to-moderate depression (dysthymia) and moderate mania (hypomania).
