Sleep architecture in insomniacs with severe benzodiazepine abuse.

OBJECTIVE: Benzodiazepines (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.

METHODS: Twenty 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.

RESULTS: Significant 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.

CONCLUSIONS: Our 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.

SIGNIFICANCE: The long term use of high doses of BZDs for chronic insomnia induces a marked depression of slow wave activity and of its physiological instability.