Sleep and depression.

Abstract

Manifestations of sleep disturbances can potentially serve as external criteria for the diagnosis of specific subtypes of major depressive disorder (MDD). Depressed patients generally experience disturbances of sleep continuity and rapid eye movement (REM) sleep. Disturbances in nonrapid eye movement (NREM) sleep (stages III and IV) also occur. Characteristic of primary sleep disturbance in many depressed patients are shortened REM latency periods and instabilities in NREM sleep identified by increases in the number of stage shifts, decreases in the duration of stage III and IV sleep, and a shift towards lighter sleep stages (sleep efficiency disturbances). Treatment modalities for these sleep disturbances include sleep deprivation therapy and antidepressant therapy. Sleep deprivation alone has been only moderately successful, while antidepressant therapy usually results in symptomatic improvement. To restore normative sleep, REM sleep periods and stage III and IV sleep must be returned to normal. Trazodone therapy has been shown to reduce the frequency of arousals, the severity of drowsiness, and the duration of REM sleep, and increase restorative slow wave sleep and stage III and IV NREM sleep.