title: Risk factors for incident chronic insomnia: a general population prospective study.
abstract: OBJECTIVE
  The few population-based, prospective studies that have examined risk factors of incident insomnia were limited by small sample size, short follow-up, and lack of data on medical disorders or polysomnography. We prospectively examined the associations between demographics, behavioral factors, psychiatric and medical disorders, and polysomnography with incident chronic insomnia.
  
  
  METHODS
  From a random, general population sample of 1741 individuals of the adult Penn State Sleep Cohort, 1395 were followed-up after 7.5 years. Only subjects without chronic insomnia at baseline (n = 1246) were included in this study. Structured medical and psychiatric history, personality testing, and 8-h polysomnography were obtained at baseline. Structured sleep history was obtained at baseline and follow-up.
  
  
  RESULTS
  Incidence of chronic insomnia was 9.3%, with a higher incidence in women (12.9%) than in men (6.2%). Younger age (20-35 years), non-white ethnicity, and obesity increased the risk of chronic insomnia. Poor sleep and mental health were stronger predictors of incident chronic insomnia compared to physical health. Higher scores in MMPI-2, indicating maladaptive personality traits, and excessive use of coffee at baseline predicted incident chronic insomnia. Polysomnographic variables, such as short sleep duration or sleep apnea, did not predict incident chronic insomnia.
  
  
  CONCLUSIONS
  Mental health, poor sleep, and obesity, but not sleep apnea, are significant risk factors for incident chronic insomnia. Focusing on these more vulnerable groups and addressing the modifiable risk factors may help reduce the incident of chronic insomnia, a common and chronic sleep disorder associated with significant medical and psychiatric morbidity and mortality.
authors.affiliation: Sleep Research & Treatment Center, Penn State University College of Medicine, Hershey, PA, United States. rsingareddy@hmc.psu.edu
authors.forename: Ravi
authors.initials: R
authors.lastname: Singareddy
authors.forename: Alexandros N
authors.initials: AN
authors.lastname: Vgontzas
authors.forename: Julio
authors.initials: J
authors.lastname: Fernandez-Mendoza
authors.forename: Duanping
authors.initials: D
authors.lastname: Liao
authors.forename: Susan
authors.initials: S
authors.lastname: Calhoun
authors.forename: Michele L
authors.initials: ML
authors.lastname: Shaffer
authors.forename: Edward O
authors.initials: EO
authors.lastname: Bixler
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000453:epidemiology; D003069:Coffee; D003863:Depression / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008950:MMPI; D008297:Male; D008603:Mental Health / Q000706:statistics & numerical data*; D008875:Middle Aged; D009017:Morbidity; D009765:Obesity / Q000453:epidemiology*; D010414:Pennsylvania / Q000453:epidemiology; D010551:Personality; D017286:Polysomnography; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D012907:Smoking / Q000453:epidemiology; D055815:Young Adult
chemical_list: D003069:Coffee