The role of personality traits in insomnia.

Insomnia is a highly prevalent sleep disorder, known to affect psychological well-being and quality of life. While perpetuating factors have received much attention, the role of predisposing factors has not been studied in much detail. The susceptibility to develop insomnia may be linked to the presence of certain personality features. Here, we review studies that assessed this particular aspect of insomnia. Due to various methodological issues, definitive conclusions cannot be drawn as of yet, and several conflicting findings remain. However, there is a common trend indicating that insomniacs display more signs of 'neuroticism', 'internalization', anxious concerns and traits associated with perfectionism. These factors may play varying roles depending on the specific subdiagnosis of insomnia. In addition, certain personality traits may be related to the response to (cognitive) behavioral treatment. For instance, insomniacs reporting less 'guardedness' and have a higher score on the MMPI 'hypomania' scale show less improvement through psychological treatment. The specific role of personality traits in the etiology of insomnia is not yet clear, because of a lack of longitudinal data. Personality factors may play a causal role in the development of insomnia, but may also be a consequence of the sleep problem and the associated daytime dysfunction. Future longitudinal studies should not view personality as a single predisposing factor, but assess it as a part of a larger group of interacting psychological and physiological factors involved in the predisposition to and perpetuation of chronic insomnia.

Self-help treatment for insomnia through television and book: a randomized trial.

OBJECTIVE: Recently, a Dutch educational broadcasting company developed a 6 week self-help course for insomnia, which consists of a book and television programmes. In this study we examined its effects. METHODS: 247 subjects with sleep problems were recruited through the media and randomized to the self-help treatment (n=126) or a waiting list control group (n=121). The intervention group received the book, and for 6 consecutive weeks a DVD or videotape. Subjects were assessed before and after the course. RESULTS: Both groups improved significantly with respect to sleep but there were no significant differences in improvements between the groups. However, the intervention group improved significantly more on secondary outcomes: the subjective evaluation of sleep quality (d=0.65), dysfunctional beliefs and attitudes about sleep (d=0.62), depressive symptoms (d=0.35), and quality of life (d=0.34). CONCLUSION: Cognitive-behavioral self-help treatment does not necessarily lead to sleep improvements but it does improve coping with insomnia. PRACTICE IMPLICATIONS: About 2% of the Dutch adult population has watched the regular broadcastings of the course after the trial ended. This huge number of viewers underlines that there is a need for this type of low cost self-help treatment.

Cognitive behavioral treatment in clinically referred chronic insomniacs: group versus individual treatment.

In this study, we compared the effect of group and cognitive behavioral treatment (CBT) in clinically referred patients with chronic insomnia. The participants were 32 individually treated primary insomniacs and 74 individuals with either primary or secondary insomnia treated in a group (5-7 patients per group). The primary outcome measures were subjective sleep, quality of life (QOL), and psychological well-being. CBT produced significant changes in sleep onset latency, total sleep time, sleep efficiency, and wake after sleep onset. For total sleep time and sleep efficiency, the improvements were maintained at follow-up as well. In the questionnaires, significant improvements from treatment were seen for the Sickness Impact Profile, Sleep Evaluation Form, and Dysfunctional Beliefs and Attitudes About Sleep. All these improvements remained significant at follow-up. We conclude that CBT for insomnia is effective for both individual and group treatment. Improvements were seen in subjective sleep parameters, QOL, attitudes about sleep, and sleep evaluation in general, both posttreatment and at follow-up.

Initial validation of the SLEEP-50 questionnaire.

Initial psychometric properties of the SLEEP-50 questionnaire, designed to detect sleep disorders as listed in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., Text Revision), were examined. The sample consisted of 377 college students, 246 sleep patients, 32 nightmare sufferers, and 44 healthy volunteers. The internal consistency was high (Cronbach's alpha = .85); test-retest correlations fell between .65 and .89. Principal component analysis with a direct oblimin rotation revealed a factor structure that closely matched the designed structure. Sensitivity and specificity scores were promising for all sleep disorders; the agreement between all clinical diagnoses and SLEEP-50-classifications was substantial (kappa = .77). These initial findings indicate that the SLEEP-50 seems able to detect a variety of sleep disorders. The SLEEP-50 can aid in screening for common sleep disorders in the general population.