Sleep architecture in insomniacs with severe benzodiazepine abuse

•Long term abuse of benzodiazepines induced only mild alterations of sleep architecture.•A depression of slow wave power activity during NREM sleep occurred in benzodiazepine abusers.•A suppression of the cyclic alternating pattern rate was the main finding in benzodiazepine abusers.

ObjectiveBenzodiazepines (BZDs) are the most commonly prescribed compounds in insomnia. A long-term of BZDs use may cause dependence and abuse. The aim of this study was to evaluate sleep architecture and microstructure (in terms of cyclic alternating pattern - CAP - analysis and of sleep EEG power spectral analysis) in a group of long-term users of high doses of BZDs for their primary chronic insomnia.MethodsTwenty patients consecutively admitted at the Sleep Centre for drug discontinuation and 13 matched healthy controls underwent a full nocturnal video-polysomnographic recording, after one adaptation night.ResultsSignificant differences were found in time in bed, REM sleep latency and sleep stage 1% which were increased in patients compared to controls, while CAP rate was dramatically decreased. During NREM sleep, patients showed a clear decrease in the relative power of delta band.ConclusionsOur data demonstrate that in adults with chronic insomnia, long-term use of high doses of BZDs induces a severe disruption of sleep microstructure, while sleep architecture seems to be much less affected.SignificanceThe long term use of high doses of BZDs for chronic insomnia induces a marked depression of slow wave activity and of its physiological instability.