Lithium delays circadian phase of temperature and REM sleep in a bipolar depressive: a case report.

The effects of lithium on the circadian rhythms of body temperature and rapid eye movement (REM) sleep were examined in a patient with bipolar depression. The acrophase of body temperature showed a phase delay of 74 min after 1 week of lithium treatment. REM latency increased significantly with lithium, and the onset of subsequent REM periods was also delayed. The proportion of the night spent in REM sleep decreased significantly. There was no effect of lithium on the patient's mood. The data are consistent with the hypothesized phase-delaying properties of lithium but do not support the causal link between circadian phase and affective state.