Effect of pharmacologic treatments on the sleep of depressed patients

Antidepressant drugs produce striking effects on sleep architecture that are best understood in terms of their interactions with the monoamine pathways controlling sleep and wakefulness. Many different antidepressant drugs, including tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs), and selective 5-hydroxytryptamine (5-HT; serotonin) reuptake inhibitors (SSRIs), decrease rapid eye movement (REM) sleep. The reduction in REM sleep produced by antidepressants may be an important part of their mechanism of action; however, the ability of new antidepressant compounds, such as nefazodone and moclobemide, to increase REM sleep throws doubt on this suggestion. The effects of antidepressants on slow-wave sleep (SWS) are quite diverse; in general, antidepressants having significant 5-HT2A/2C receptor antagonist properties increase SWS, whereas other drugs, such as SSRIs or MAOIs, either lower SWS or produce no change. Sleep continuity is improved acutely following administration of antidepressants with sedating properties such as certain TCAs, trazodone, and mianserin. Some nonsedating drugs (ritanserin and nefazodone) also improve sleep continuity measures, possibly through 5-HT2A/2C receptor blockade.