Sleep changes in smokers before, during and 3 months after nicotine withdrawal.

Nicotine may affect sleep by influencing sleep-regulating neurotransmitters. Sleep disorders can increase the risk for depression and substance dependency. To detect the influence of sleep disturbances on the effect of smoking cessation, we investigated polysomnographically (PSG) the sleep of smoking subjects during a period of smoking, during withdrawal and after a period of abstinence from nicotine. Thirty-three smokers (23 male, 10 female, median age 29 years, Fagerström Test for Nicotine Dependence score 6.3) were examined during smoking, 24-36 hours after smoking and 3 months after cessation. All subjects had an adaptation night followed by the PSG night. Compared with the smoking state, we found increased arousal index and wake time during nicotine withdrawal. Smokers who later relapsed (11) presented a higher degree of nicotine dependence and more withdrawal symptoms than those who abstained (22) and were characterized by less rapid eye movement (REM) sleep, a longer REM latency as well as by more intense sleep impairments in the subjective sleep rating during the withdrawal. Impairments of sleep during the withdrawal phase may reflect more severe nicotine dependence and may contribute to earlier relapse into smoking behaviours.