The development of insomnia within the first year: a focus on worry.

Department of Occupational and Environmental Medicine, Orebro University Hospital, Orebro, Sweden. markus.janson@orebroll.se

OBJECTIVES: The aim of this investigation was to study the relationships between sleep-related worry and subjective sleep perception as a function of stage of chronicity. DESIGN: A cross-sectional study consisting of 136 individuals with a short history of insomnia was used. METHODS: The 136 participants were grouped to form two different levels of chronicity based on their duration of insomnia: short (3-7 months; n=69) and long (>7-12 months; n=67). Two domains of sleep-related worry (sleeplessness and health) were used as predictors of subjective sleep perception (sleep onset latency, time awake after sleep onset, and total sleep time). RESULTS: The association between worry for sleeplessness and subjective sleep perception was significantly different across the stages of chronicity. In the group with a short duration of insomnia, worry for sleeplessness was not related to subjective sleep perception. Worry for sleeplessness was however a significant predictor of subjective sleep perception in the group with a long duration of insomnia (unique variance: 33% on sleep onset latency, 19% on time awake after sleep onset, and 13% on total sleep time). Even if marked differences were observed between the two groups, worry for health was not significantly different across stages of chronicity on subjective sleep perception. CONCLUSIONS: This suggests that the role of sleep-related worry to subjective sleep perception may increase over time. Given that worry was a mechanism with an increasingly stronger impact over time, this supports the idea that worry is a potential mechanism related to the development of insomnia.

PMID: 16870058 [PubMed - indexed for MEDLINE]