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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.

SUMMARYThe validity of sleep laboratory investigations in patients with insomnia is important for researchers and clinicians. The objective of this study was to examine the first-night effect and the reverse first-night effect in patients with chronic primary insomnia compared with good sleeper controls. A retrospective comparison of a well-characterised sample of 50 patients with primary insomnia and 50 good sleeper controls was conducted with respect to 2 nights of polysomnography, and subjective sleep parameters in the sleep laboratory and the home setting. When comparing the first and second sleep laboratory night, a significant firstnight effect was observed across both groups in the great majority of the investigated polysomnographic and subjective variables. However, patients with primary insomnia and good sleeper controls did not differ with respect to this effect. Regarding the comparison between the sleep laboratory nights and the home setting, unlike good sleeper controls, patients with primary insomnia reported an increased subjective sleep efficiency on both nights (in part due to a reduced bed time) and an increased subjective total sleep time on the second night. These results suggest that even the second sleep laboratory night does not necessarily provide clinicians and researchers with a representative insight into the sleep perception of patients with primary insomnia. Future studies should investigate whether these findings also hold for other patient populations. IN TROD UCTI ONThe first-night effect (FNE) describes the common phenomenon that individuals sleep worse during the first sleep laboratory night than during subsequent sleep laboratory nights. The FNE is assumed to be a consequence of an adaptation process to the sleep laboratory setting (Coble et al., 1974) caused by the discomfort of the electrodes and by potential psychological consequences of the diagnostic evaluation (Le Bon et al., 2001;Riedel et al., 2001). Several studies have shown the FNE in healthy good sleepers and different patient populations (Agnew et al., 1966;Edinger et al

have investigated attentional preference for sleep-related cues in primary insomnia using computerized tasks. [20][21][22][23][24][25][26] The majority of this work supports the notion that poor sleepers show an attentional bias for sleep-related stimuli relative to good sleeper controls. Consistent with these results, altered emotional responses to sleep-related stimuli have been reported in people with insomnia as compared to good sleepers. 27 Of note, studies on anxiety suggest a direct causal link from facilitated selective attention to worry. 28Although an enhanced attentional focus towards sleep-related cues may be involved in the development and maintenance of chronic insomnia, several important questions have not been answered up to now. First, little effort has been made to investigate the relationship between cognitive arousal and objectively determined sleep parameters, and the studies that have been carried out have reported inconsistent results. For example, van Egeren et al.14 found no signifi cant correlation between pre-sleep cognitive activity and polysomnographiStudy Objectives: The present study aimed at further investigating trait aspects of sleep-related cognitive arousal and general cognitive arousal and their association with both objective and subjective sleep parameters in primary insomnia patients. Methods: A clinical sample of 182 primary insomnia patients and 54 healthy controls was investigated using 2 nights of polysomnography, subjective sleep variables, and a questionnaire on sleep-related and general cognitive arousal. Results: Compared to healthy controls, primary insomnia patients showed both more sleep-related and general cognitive arousal. Furthermore, sleep-related cognitive arousal was closely associated with measures of sleep-onset and sleep-maintenance problems, while general cognitive arousal was not. Conclusions: Cognitive-behavioral treatment for insomnia might benefi t from dedicating more effort to psychological interventions that are able to reduce sleep-related cognitive arousal. Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Germany S C I E N T I F I C I N V E S T I G A T I O N SI nsomnia is one of the most prevalent health complaints worldwide. It is defi ned by diffi culties initiating or maintaining sleep or non-restorative sleep, accompanied by signifi cant daytime impairments.1 Chronic insomnia affects up to 22% of the population 2 and commonly occurs as a comorbid condition in other medical or mental disorders. Primary insomnia, an exclusionary diagnosis of poor sleep, ruling out psychiatric, medical, and additional sleep-related pathology, 3 is estimated to affect up to 3% of the population. 4 Current models of primary insomnia highlight the role of cognitive, emotional, and physiological hyperarousal for the development and maintenance of the disorder. [5][6][7][8][9] With respect to cognitive processes, patients' cognitions are often dominated by worries and ruminations that are associated with a level of arousal that ...