Sleep-related safety behaviours predict insomnia symptoms 1 year later in a sample of university students.

Several studies have demonstrated the relevance of cognitive factors in the development of insomnia complaints, but very few have investigated how these factors influence the development of insomnia complaints over time. In this study we set out to investigate key factors associated with present insomnia severity and the development of insomnia complaints over time. We employed a two-wave longitudinal design where we measured insomnia severity, pre-sleep arousal, dysfunctional beliefs about sleep, sleep-related worry and safety-behaviours in a sample of students at baseline and 1 year later. At baseline, 353 respondents filled in the questionnaires and 79 completed these a year later. In the cross-sectional analyses, pre-sleep arousal and sleep-related worry were unique contributors to insomnia severity. Using baseline data to predict insomnia severity 1 year later, only sleep-related safety emerged as a predictor. These findings suggest that sleep-related worry and pre-sleep arousal are the primary factors influencing current severity. In terms of development and/or persistence, sleep safety may constitute a potentially underestimated factor.