Effects of abstinence from smoking on sleep and daytime sleepiness.

This study examined the effect of smoking abstinence on sleep quality, daytime sleepiness, and mood in 18 subjects (10 men and 8 women) aged 35 to 49 years who had smoked at least 20 cigarettes per day for more than 2 years. Subjects were studied on two consecutive weeks following an adaptation night. During week 1 (study nights 1, 2, and 3), the subjects smoked as usual. Smoking abstinence was mandatory during week 2 beginning 3 h prior to night 4 and ending after the final tests on night 6. Complete sleep monitoring each night was followed by multiple sleep latency tests (MSLTs) throughout the day. Psychomotor tests and mood observations were performed throughout the day between the MSLTs. The results of testing when the subjects smoked were compared with those during nonsmoking days and nights. Nights 1 and 4 were considered adaptation nights and not included in the analysis. Overnight studies showed a significant increase in the number of relative arousals (a change in sleep stage to wake, stage 1 sleep, or movement), stage changes, and awakenings during smoking cessation. The MSLT latency to stage 1 sleep decreased during smoking cessation. Also during abstinence, the subjects reported that they felt more irritable, had increased feelings of anxiety, felt greater tension, and had more cravings for cigarettes. We conclude that smoking cessation is associated with increased daytime sleepiness and impaired mood. The daytime sleepiness may be due to the combination of sleep disturbance and withdrawal of the nicotine normally provided through smoking.