BIMODAL DISTRIBUTION OF REM-SLEEP LATENCIES IN DEPRESSION

Abstract

The REM [rapid eye movement] sleep latency of endogenously depressed patients was investigated by analyzing 90 polysomnograms of 6 patients during depression and 58 polysomnograms of 4 of these patients after remission. During depression the REM sleep latencies are distributed bimodally with peaks at sleep onset (sleep onset REM phases, SOREMP) and 60 min later. During the follow-up examinations some time after remission, the occurrence of SOREMP is very rare. A model is proposed where the occurrence of SOREMP in the sleep of these patients is caused by a reduced amplitude of the circadian rhythm of the arousal system.