title: The role of sleep problems in the development of depression in those with persistent pain: a prospective cohort study.
abstract: OBJECTIVE
  One theoretical model suggests a pathway between pain and the development of depression through sleep problems. Here, we prospectively test the hypothesis that incident sleep problems, in those with persistent pain, increase risk of new onset probable depression, and investigate the role of "pain that interferes with daily life" (pain interference) on this pathway.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Community based population study within UK.
  
  
  METHODS
  Participants with persistent pain nested within a larger longitudinal community study.
  
  
  METHODS
  Participants were mailed health questionnaires at baseline (time 1) with follow-up at 3 years (time 2) and 6 years from baseline (time 3). Questionnaires at baseline and at follow up contained measures of sleep problems (Jenkins Sleep Questionnaire), depressive symptoms (Hospital Anxiety and Depressive Scale), and pain interference.
  
  
  RESULTS
  In total, 2,622 participants returned health questionnaires at all time points and indicated the presence of pain at each time point. After adjustment for age, gender, marital status, employment status, alcohol intake, smoking status, and body mass index, having a new period of sleep problems at year 3 more than trebled the risk of a new period of probable depression at year 6 (relative risk 3.47, 95% CI 1.97 to 6.03). Mediation analysis showed that pain interference played a significant but relatively minor role in the pathway.
  
  
  CONCLUSIONS
  Clinicians treating patients with persistent pain may wish to consider options that involve addressing the prevention or treatment of sleep problems, in addition to their primary focus of pain management.
authors.affiliation: Arthritis Research UK Primary Care Centre, Keele University, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Campbell
authors.forename: Nicole
authors.initials: N
authors.lastname: Tang
authors.forename: John
authors.initials: J
authors.lastname: McBeth
authors.forename: Martyn
authors.initials: M
authors.lastname: Lewis
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Main
authors.forename: Peter R
authors.initials: PR
authors.lastname: Croft
authors.forename: Hannah
authors.initials: H
authors.lastname: Morphy
authors.forename: Kate M
authors.initials: KM
authors.lastname: Dunn
mesh_terms: D000203:Activities of Daily Living; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000009:adverse effects; D059350:Chronic Pain / Q000150:complications* / Q000523:psychology; D003863:Depression / Q000209:etiology*; D004651:Employment / Q000523:psychology; D006801:Humans; D008297:Male; D017533:Marital Status; D008875:Middle Aged; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000150:complications* / Q000209:etiology / Q000523:psychology; D011795:Surveys and Questionnaires
keywords: Persistent pain; cohort; depression; pain interference; sleep problems