title: Associations between psychological factors and nighttime/daytime symptomatology in insomnia.
abstract: OBJECTIVE
  The aim of this study was to examine psychological factors in insomnia and the association between psychological mechanisms and nighttime and daytime symptoms.
  
  
  METHODS
  A cross-sectional examination in the general population was used. The study sample consisted of 1890 participants from the general population. The participants completed a survey on nighttime and daytime symptoms, health outcomes, and psychological factors.
  
  
  RESULTS
  Relative to poor and normal sleepers, the insomnia group had higher scores on worry, beliefs, physiologic arousal, monitoring/attentional bias, and safety behaviors than the other two groups, and the poor sleepers exhibited a similar pattern relative to the normal sleepers. High total wake time was associated with more worry, physiologic arousal, and safety behaviors (26.3% variance), low sleep restoration with more worry, unhelpful beliefs, and monitoring/attentional bias (28.2% variance), and low sleep quality with higher scores on all the psychological mechanisms (35.8% variance). Elevated daytime symptoms were related to more unhelpful beliefs and monitoring/attentional bias (44.3% variance).
  
  
  CONCLUSIONS
  The findings indicate that psychological factors are linked to nighttime and daytime symptomatology in insomnia.
authors.affiliation: Department of Psychology, Stockholm University, SE-106 91 Stockholm, Sweden. markus.janssonfrojmark@psychology.su.se
authors.forename: Markus
authors.initials: M
authors.lastname: Jansson-Fröjmark
authors.forename: Allison G
authors.initials: AG
authors.lastname: Harvey
authors.forename: Annika
authors.initials: A
authors.lastname: Norell-Clarke
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Linton
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001007:Anxiety / Q000150:complications / Q000523:psychology; D001143:Arousal; D001288:Attention; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D015438:Health Behavior; D007722:Health Knowledge, Attitudes, Practice; D006304:Health Status; D006306:Health Surveys / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D017440:Photoperiod; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D007319:Sleep Initiation and Maintenance Disorders / Q000150:complications / Q000175:diagnosis / Q000523:psychology*; D012893:Sleep Wake Disorders / Q000150:complications / Q000523:psychology; D013548:Sweden; D063189:Symptom Assessment / Q000379:methods / Q000523:psychology* / Q000706:statistics & numerical data