Polysomnographic Findings in a Cohort of Chronic Insomnia Patients with Benzodiazepines Abuse

Study objectives: to evaluate sleep modifications induced by chronic benzodiazepines (BDZs) abuse. \r\nMethods: cohort study, comparison of sleep measures between BDZs abusers and controls. Drug Addiction Unit (Institute of Psychiatry) and Unit of Sleep Disorder (Institute of Neurology) of the Catholic University in Rome. \r\nSix outpatients were enrolled, (4 men and 2 7 women, mean age 53.3±14.8, range: 34 - 70 years) affected by BDZ chronic abuse; 55 healthy controls (23 men and 32 women, mean age 54.2 ±13.0, range: 27–76 years). \r\nAll patients underwent clinical evaluation, psychometric measures, ambulatory polysomnography, scoring \r\nof sleep macrostructure and microstructure (power spectral fast-frequency EEG arousal, Cyclic Alternating Pattern - CAP), Heart Rate Variability. \r\nResults: BDZs abusers had relevant modification of sleep macrostructure and a marked reduction of fast-frequency EEG arousal in NREM (Patients: 6.6±3.7 events/hour, Controls 13.7±4.9 events/hour, U-test: 294, p=0.002) and REM (Patients: 8.4±2.4 events/hour, Controls 13.3±5.1 events/hour, U-test: 264, p=0.016), and of CAP rate (Patients: 15.0±8.6 %, Controls: 51.2±12.1 %, U-test: 325, p<0.001). \r\nDiscussion: BDZs abusers have reduction of arousals associated with increased number of \r\nnocturnal awakenings and severe impairment of sleep architecture. The effect of chronic \r\nBDZs abuse on sleep may be described as a severe impairment of arousal dynamics; the result is the \r\ninability to modulate levels of vigilance.