title: The risk for depression comorbidity in patients with COPD.
abstract: BACKGROUND
  Patients with COPD are believed to have a high risk for the development of depression. However, it remains unclear whether or not there is a temporal relation between COPD and depression, and if the higher risk for depression is a result of having a chronic disease, or is specific for COPD. The aim of this study is to compare the risk for physician-diagnosed depression in patients with COPD, patients with diabetes mellitus (DM), and control subjects without chronic conditions.
  
  
  METHODS
  The study was a prospective cohort study based on the Continuous Morbidity Registration database. Cox proportional hazards analysis was used to identify the risk of a first episode of depression in patients with COPD compared to patients with DM and matched control subjects without chronic conditions. The following covariates were added to the model: age, the general practice the patient was listed with, socioeconomic status, comorbidity, and gender. All patients with a diagnosis of depression preceding the date of first diagnosis of COPD or DM (dummy date in control subjects) were excluded.
  
  
  RESULTS
  The hazard ratios for a first episode of depression in the COPD group compared to the DM group and healthy controls subjects were 1.80 (95% confidence interval [CI], 1.16 to 2.81) and 1.68 (95% CI, 1.20 to 2.35), respectively.
  
  
  CONCLUSIONS
  We found a temporal relation between COPD and physician-diagnosed depression. Patients with COPD are more likely to have depression diagnosed than patients with DM and control subjects without chronic conditions.
authors.affiliation: Department of General Practice, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands. Electronic address: L.vandenbemt@hag.umcn.nl.
authors.forename: Lisette
authors.initials: L
authors.lastname: van den Bemt
authors.affiliation: Department of General Practice, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
authors.forename: Tjard
authors.initials: T
authors.lastname: Schermer
authors.affiliation: Department of General Practice, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Bor
authors.affiliation: Nursing Home Department, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
authors.forename: Renate
authors.initials: R
authors.lastname: Smink
authors.affiliation: Department of General Practice, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
authors.forename: Evelyn
authors.initials: E
authors.lastname: van Weel-Baumgarten
authors.affiliation: Department of General Practice, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Lucassen
authors.affiliation: Department of General Practice, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
authors.forename: Chris
authors.initials: C
authors.lastname: van Weel
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D002908:Chronic Disease; D015331:Cohort Studies; D003866:Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology*; D003920:Diabetes Mellitus / Q000523:psychology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000523:psychology*; D018570:Risk Assessment; D012959:Socioeconomic Factors; D013997:Time Factors