title: Comorbidity of major depression with substance use disorders.
abstract: OBJECTIVE
  In the Canadian adult population, we aimed to 1) estimate the 12-month prevalence of major depressive disorder (MDD) in persons with a diagnosis of harmful alcohol use, alcohol dependence, and drug dependence; 2) estimate the 12-month prevalence of harmful alcohol use, alcohol dependence, and drug dependence in persons with a 12-month and lifetime diagnosis of MDD; 3) identify socioeconomic correlates of substance use disorder-major depression comorbidity; 4) determine how comorbidity impacts the prevalence of suicidal thoughts; and 5) determine how comorbidity affects mental health care used.
  
  
  METHODS
  We examined data from the Canadian Community Health Survey: Mental Health and Well-Being (CCHS 1.2).
  
  
  RESULTS
  The 12-month prevalences of MDD in persons with a substance use disorder (SUD) were 6.9% for harmful alcohol use (95% confidence interval [CI], 5.2 to 8.5), 8.8% for alcohol dependence (95%CI, 6.6 to 11.0), and 16.1% for drug dependence (95%CI, 10.3 to 21.9). Conversely, the 12-month prevalences of harmful alcohol use, alcohol dependence, and drug dependence in persons with a 12-month diagnosis of MDD were 12.3% (95%CI, 9.4 to 15.2), 5.8% (95%CI, 4.3 to 7.3), and 3.2% (95%CI, 2.0 to 4.4), respectively. Regression modelling did not identify any socioeconomic predictors of SUD-MDD comorbidity. Substance dependence and MDD independently predicted higher prevalence of suicidal thoughts and mental health treatment use.
  
  
  CONCLUSIONS
  SUDs cooccur with a high frequency in cases of MDD. Clinicians and mental health services should consider routine assessment of SUDs in depression patients.
authors.affiliation: Department of Psychiatry, University of Calgary, Alberta. scurrie@ucalgary.ca
authors.forename: Shawn R
authors.initials: SR
authors.lastname: Currie
authors.forename: Scott B
authors.initials: SB
authors.lastname: Patten
authors.forename: Jeanne V A
authors.initials: JV
authors.lastname: Williams
authors.forename: JianLi
authors.initials: J
authors.lastname: Wang
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Beck
authors.forename: Nady
authors.initials: N
authors.lastname: El-Guebaly
authors.forename: Colleen
authors.initials: C
authors.lastname: Maxwell
mesh_terms: D000293:Adolescent; D000328:Adult; D002170:Canada / Q000453:epidemiology; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D012959:Socioeconomic Factors; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology*