Ethanol as a hypnotic in insomniacs: Self administration and effects on sleep and mood

The purpose off his study was to assess the effects of low ethanol doses on sleep and mood and to assess its reinforcing effects used as a hypnotic. T wenty healthy adults, aged 21-45 yrs, all moderate social drinkers, were st udied: eleven subjects had insomnia and nine were normal sleepers, as docum ented by clinical polysomnography. On two sampling nights each, ethanol (0. 5 g/kg) or placebo was administered before sleep in color-coded cups presen ted in three doses (0.2, 0.2, and 0.2 g/kg) separated by 15 min. On three s ubsequent nights subjects chose their preferred pre sleep beverage (0.2 g/k g ethanol or placebo) based on cup color and were given an opportunity for 3 additional refills (0.2 g/kg each) of the chosen beverage at 15 min inter vals, yielding a total possible dose of 0.8 g/kg. Insomniacs chose ethanol 67% of nights and normals 22%. Insomniacs chose significantly more ethanol refills than normals for an average nightly dose of 0.45 g/kg and normals t ook significantly more placebo refills. On the sampling nights 0.5 g/kg eth anol reduced REM sleep for both groups for the 8-hr sleep period and in ins omniacs increased stage 3-4 sleep and reduced stage I sleep during the firs t half-of the night to the level seen in the normals. Other sleep variables were not altered in either group or halves of the night. Pre-sleep improve ments in the Profile of Mood States tension and concentration factors were also associated with ethanol administration. Thus, acutely, both sleep and mood effects appear to be associated with the reinforcing effects of ethano l as a hypnotic for insomniacs. [Neuropsychopharmacology 20:279-286, 1999] (C) 1999 American College of Neuropsychopharmacology. Published by Elsevier Science Inc.