Effects of Antidepressants on Sleep

Kim, Gyu Ho; Yang, Chang Kook

Abstract

The diverse effects of antidepressants on sleep are mediated by their agonistic or antagonistic properties on specific neurotransmitters: the catecholamine, serotonergic, cholinergic, and histaminergic neurotransmitter systems, which also regulate the timing and cycling of sleep. Therefore, antidepressants can have both class- and compound-specific effects on sleep/wake dynamics, sleep stages, and on motor control during sleep. For these reasons, the sedating or wake-promoting effects of these medications are important factors influencing specific drug selection. As these sleep-related effects may in turn influence both medication compliance as well as the course of the disease state itself, it is important for clinicians to understand and predict the possible effects of antidepressants on sleep. Some antidepressants, such as amitriptyline, doxepine, trazodone, and mirtazapine, possess sedating properties and improve sleep continuity via alpha-1 adrenoceptors and histamine H1 receptor blockade, combined with 5HT(2A/2C) receptor blockade. Other antidepressants, such as SSRI, SNRI and MAOIs, worsen sleep and may cause insomnia, an effect which may be linked to facilitation of 5HT(2A/2C) receptors. The majority of antidepressants are REM (rapid eye movement) suppressants, though some, such as nefazodone, bupropion, and mirtazapine, lack REM-suppressing effects. On the other hand, the effects of antidepressants on slow wave sleep (SWS) are much less consistent than their effects on REM sleep. Available data suggest that antidepressants, including some TCAs, and trazodone, increase SWS, possibly as a function of their 5-HT(2A/2C) receptor antagonism. In contrast, antidepressants lacking 5-HT(2A/2C) receptor antagonist effects, including SSRIs, SNRIs and MAOIs, may produce no change or even decrease in SWS. Knowledge of the effects of antidepressants on sleep will be helpful in estimating the sleep disturbance caused by these compounds, and can thus help in the selection of appropriate compound for individual patients.