Introduction
Everyone experiences some unhappiness, often as a result of a change, either in the form of a setback or a loss, or simply, as Freud said, "everyday misery." The painful feelings that accompany these events are usually appropriate, necessary, and transitory, and can even present an opportunity for personal growth. However, when depression persists and impairs daily life, it may be an indication of a depressive disorder. Severity, duration, and the presence of other symptoms are the factors that distinguish normal sadness from a depressive disorder.
Depression has been alluded to by a variety of names in both medical and popular literature for thousands of years. Early English texts refer to "melancholia," which was for centuries the generic term for all emotional disorders.
Depression is now referred to as a mood disorder, and the primary subtypes are major depression, dysthymia (chronic and usually milder depression), and atypical depression. Other important forms of depression are premenstrual dysphoric disorder (PDD or PMDD) and seasonal affective disorder (SAD).

The other major mood disorder is bipolar disorder, or manic-depressive illness, which is characterized by periods of depression alternating with episodes of excessive energy and activity. Bipolar disorder is not discussed in this report. See In-Depth Report #66: Bipolar disorder.
Major Depression
In major, or acute, depression, at least five of the symptoms listed below must occur for a period of at least 2 weeks, and they must represent a change from previous behavior or mood. Depressed mood or loss of interest must be present.
Symptoms:
1. Depressed mood on most days for most of each day -- irritability may be prominent in children and adolescents
2. Total or very noticeable loss of pleasure most of the time
3. Significant increases or decreases in appetite, weight, or both






Previous Section















