Effects of lithium carbonate on the clinical picture and the sleep of depressive patients.

5 patients with endogenous depression of uni- and bipolar type, classified according to sleep characteristics as normo- (1), hypo- (3) and hypersomniacs (1), were treated for 3 weeks with a daily dose of 900 mg lithium carbonate. Polygraphic sleep recordings were taken in every patient in the course of 3 placebo nights, 3 nights during therapy and 2 registrations after lithium carbonate was discontinued. Before therapy, a prolonged sleep and a shortened REM latency were observed, which were changed in the course of the treatment especially in the normosomniac patient. In the other examined sleep parameters (total sleep time, sleep efficiency, percentage of REM sleep, slow wave sleep), discrepancies among hypo-, hyper- and normosomniac patients were present. From the clinical point of view all patients showed an improvement subjectively and objectively measured by means of Hamilton and Beck questionnaires for depression. This study emphasizes the necessity of administering daily lithium carbonate doses higher than 900 mg because of only a mild therapeutic effect.