The effects of
lithium carbonate on sleep patterns have been investigated both acutely in normal and depressed subjects and chronically in depressed subjects. In normal subjects receiving
lithium for two weeks total sleep time did not vary, REM sleep decreased and REM sleep latency increased. In depressed subjects, either on short therm
therapy or on long term
therapy stages 3 and 4 increased, REM sleep decreased, REM latency increased and REM activity/time spent asleep (an index of REM intensity per minute of sleep) decreased. Plasma
lithium levels were negatively correlated with REM sleep percentage and positively correlated with REM sleep latency. Besides, it has been shown in one paper that short term
therapy with
lithium caused small but significant delays in the sleep-wake circadian rhythm. These effects are of interest in view of polygraphic sleep abnormalities found in
affective disorders and possible circadian disturbances accounting for these abnormalities. Indeed
lithium might act in correcting spezial sleep abnormalities and/or circadian disturbances. In addition to its predominant use for the prophylaxis of recurrent
mania and depression,
lithium carbonate has been proposed and tried in the prophylactic treatment of abnormally prolonged sleep episodes featuring the
Kleine-Levin syndrome.