title: Period lengthening of human circadian rhythms by lithium carbonate, a prophylactic for depressive disorders.
abstract: The effect of lithium carbonate on the circadian system of man was studied. Four out of eight volunteers living without time cues in isolated huts in the arctic showed a lengthening of the periods of the body temperature rhythm, activity rhythm, and sleep/wakefulness rhythm by c. 1 h. Four of the participants did not show a change in the periods between the placebo and lithium ingestion phases. Two subjects who did not receive lithium salt showed internal desynchronization between the temperature rhythm and the sleep/wakefulness rhythm. Extreme isolation in bunkers is not necessary to allow free running of the circadian system in man. The sleep/wakefulness rhythm, which is very easy to record, was a reliable indicator of the circadian system in the internally-synchronized state.
mesh_terms: D000928:Antidepressive Agents / Q000494:pharmacology*; D001831:Body Temperature / Q000187:drug effects; D002940:Circadian Rhythm / Q000187:drug effects*; D006801:Humans; D008094:Lithium / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects; D012621:Seasons; D014851:Wakefulness / Q000187:drug effects
chemical_list: D000928:Antidepressive Agents; D008094:Lithium