title: 48-hour sleep-wake cycles in manic-depressive illness: naturalistic observations and sleep deprivation experiments.
abstract: Wrist motor activity and sleep were monitored longitudinally in 15 rapidly cycling and 52 nonrapidly cycling manic-depressive patients. The majority of patients experienced one or more consecutive 48-hour sleep-wake cycles (alternate nights with no sleep) when they switched out of depression into mania of hypomania. During a depressive phase, nine rapidly cycling patients were asked to simulate a 48-hour sleep-wake cycle by remaining awake for 40 hours (one night's total sleep deprivation). Eight switched out of depression, and seven were rated as manic or hypomanic; indicating that sleep loss (such as occurs with spontaneous 48-hour sleep-wake cycles) may help to trigger switches from depression to mania. The 48-hour sleep-wake cycles in patients may depend on a mechanism that is normally present in all humans, since normal persons also spontaneously experience near-48 hour sleep-wake cycles in certain experimental conditions.
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology; D001714:Bipolar Disorder / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008094:Lithium / Q000494:pharmacology; D016651:Lithium Carbonate; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D010507:Periodicity; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D012892:Sleep Deprivation; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology*
chemical_list: D014150:Antipsychotic Agents; D016651:Lithium Carbonate; D008094:Lithium