title: Major depression and alcohol use disorder in adolescence: Does comorbidity lead to poorer outcomes of depression?
abstract: Comorbid major depression (MD) and alcohol use disorder (AUD), particularly in adolescents, have been shown to be associated with poorer subsequent MD outcomes.
  
  
  
  Longitudinal data were used to model associations between a four-level classification of MD/AUD during the period 15-18 years (neither; MD-only; AUD-only; comorbid MD/AUD) and MD over the period 18-35 years. These associations were then adjusted for confounding by a series of factors measured in childhood.
  
  
  
  The three disorder groups had rates of adult MD during the period 18-35 years that were significantly (p<.05) higher than that of the group with no disorder. Furthermore, those in the comorbid MD/AUD group had significantly (p <.05) higher rates of adult MD than those in the AUD-only group, and marginally (p <.10) higher rates of adult MD than those in the MD-only group. After adjustment for confounding, the difference in rates of adult MD between the MD-only group and the MD/AUD group were no longer statistically significant. The factors that explained the associations were gender, childhood behavior problems, and exposure to physical and sexual abuse.
  
  
  
  The data were obtained by self-report, and may have been subject to biases.
  
  
  
  The results of these analyses suggest that marginally higher rates of depression to age 35 amongst the comorbid MD/AUD group were explained by increased exposure to adverse childhood circumstances amongst members of the comorbid group. Adolescent MD/AUD comorbidity is likely to be a risk marker, rather than a causal factor in subsequent MD.
authors.affiliation: Christchurch Health and Development Study, Department of Psychological Medicine, University of Otago, Christchurch School of Medicine and Health Sciences, New Zealand. Electronic address: joseph.boden@otago.ac.nz.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Boden
authors.affiliation: Christchurch Health and Development Study, Department of Psychological Medicine, University of Otago, Christchurch School of Medicine and Health Sciences, New Zealand.
authors.forename: James A
authors.initials: JA
authors.lastname: Foulds
mesh_terms: D000293:Adolescent; D000328:Adult; D019973:Alcohol-Related Disorders / Q000453:epidemiology*; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012742:Sex Offenses / Q000706:statistics & numerical data; D055815:Young Adult
keywords: Alcohol use disorders; Comorbidity; Longitudinal study; Major depression