Residual symptoms in depression: prevalence and impact.

Residual symptoms are experienced by most patients being treated for depression, including those who have achieved remission. These symptoms prevent individuals from fully recovering and feeling truly "well." Often, symptoms that are related to deficits in positive affect (such as anhedonia, pessimism, and lack of motivation) persist after the other symptoms of depression (such as irritability, distress, and low mood) have resolved. Clinicians must assess patients for residual symptoms using rating scales (eg, the Patient Health Questionnaire, Clinical Positive Affect Scale) and adjust treatment to improve patients' sense of well-being and normalcy.