Depression, Sleep, and Antidepressants

Sleep disturbances are an integral feature of depressive disorders. Like the disorders themselves,the sleep disturbances associated with depression are heterogeneous, ranging from hypersomnia tomarked difficulties maintaining sleep. These difficulties are to some extent age dependent and reflectabnormalities of central nervous system arousal. Moreover, the sleep disturbances associated with depressionhave both reversible, or state-dependent, and more persistent trait-like characteristics. Polysomnographicrecordings can be used to document sleep maintenance difficulties, and they often alsoreveal reduced slow wave sleep, an early onset of the first episode of rapid eye movement (REM)sleep, and increased phasic REM sleep. A deficit of serotonergic neurotransmission, a relative increasein pontine cholinergic activity, and, perhaps, an excess of noradrenergic and corticotropinreleasinghormone activity have been implicated in the pathogenesis of the sleep disturbances of moresevere depressive disorders. Antidepressant medications have class- and compound-specific effectson polysomnographic profiles. Unlike other antidepressants, bupropion may increase or intensifyREM sleep. While no single effect of antidepressants on sleep neurophysiology is necessary or sufficientfor treatment efficacy, differences in drug effects may provide important clues to selection ofspecific medications for particular patients.