title: The development of insomnia within the first year: a focus on worry.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
authors.affiliation: Department of Occupational and Environmental Medicine, Orebro University Hospital, Orebro, Sweden. markus.janson@orebroll.se
authors.forename: Markus
authors.initials: M
authors.lastname: Jansson
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Linton
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology*; D001294:Attitude to Health; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D006801:Humans; D008875:Middle Aged; D015995:Prevalence; D012720:Severity of Illness Index; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D011795:Surveys and Questionnaires; D013997:Time Factors