Intranasal administration of oxytocin alters sleep architecture

Abstract

The role of nonapeptides in the modulation of sleep has been described by several studies; yet, little evidence is found on the effects on sleep of oxytocin (OT), a nonapetide involved in human social behaviour and in the regulation of the hypothalamo-pituitary-adrenal axis. The aim of the present study is to examine whether intranasal administration of OT has any effect on sleep architecture. Ten healthy male volunteers were included in a double-blind, cross-over study and were randomly administered nasal instillations of either placebo or OT. A one-month washout period was allowed between the administrations of each substance. Polysomnographic recordings were performed: before the beginning of drug administration, after seven days and after one month. We found that long-term administration of OT influences sleep architecture by reducing sleep latencies, increasing the sleep efficiency and increasing the percent of REM sleep episodes.