Prevention of relapse and recurrence in depression: the role of long-term pharmacotherapy and psychotherapy.

Major depressive disorder is a chronic disorder, frequently characterized by relapses and recurrences. One of the major risk factors for additional episodes of depression is the presence of residual symptoms that persist after a depressive episode ends; these residual symptoms tend to progress to another depressive episode. Although relapse or recurrence may be prevented with long-term pharmacotherapy, this approach is recommended only for patients at high risk of relapse or recurrence. Patients not at high risk who are effectively treated to full remission have a substantially lower risk of developing another depressive episode. In addition, psychotherapy, alone or combined with medication, has been shown to be effective in preventing further episodes of depression.