title: Comorbidity between alcohol dependence and illicit drug dependence in adolescents with antisocial behavior and matched controls.
abstract: BACKGROUND
  Knowledge regarding the causes of comorbidity among substance use disorders can have significant impact on future research examining the etiology of these disorders. Unfortunately, the conclusions of past studies examining the comorbidity among substance use disorders are conflicting; some studies emphasize familial influences common to multiple substances, while others emphasize substance-specific influences. Discrepancies in results may reflect different analytical approaches or differences in the samples. Here, we examine the causes of comorbidity between alcohol dependence and illicit drug dependence in adolescents.
  
  
  METHODS
  We ascertained a clinical sample of adolescents treated for antisocial behavior and substance use disorders and their siblings and a matched control sample. A model fitting approach was used to test 13 alternative hypotheses for the causes of comorbidity.
  
  
  RESULTS
  The best supported hypothesis for the comorbidity between alcohol dependence and illicit drug dependence was a model hypothesizing that comorbid disorders are alternate forms of a single underlying liability. The next best fitting models were two of the correlated liabilities models (correlated risk factors and reciprocal causation).
  
  
  CONCLUSIONS
  The results suggest that the best hypotheses explaining the comorbidity between alcohol and illicit drug dependence in adolescents are that alcohol dependence and illicit drug dependence are manifestations of a single general liability to develop substance dependence or that there are separate liabilities that are highly correlated.
authors.affiliation: Institute for Behavioral Genetics, Campus Box 447, University of Colorado, Boulder, CO 80309, USA. soo.rhee@colorado.edu
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Rhee
authors.forename: John K
authors.initials: JK
authors.lastname: Hewitt
authors.forename: Susan E
authors.initials: SE
authors.lastname: Young
authors.forename: Robin P
authors.initials: RP
authors.lastname: Corley
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Crowley
authors.forename: Michael C
authors.initials: MC
authors.lastname: Neale
authors.forename: Michael C
authors.initials: MC
authors.lastname: Stallings
mesh_terms: D000293:Adolescent; D000328:Adult; D000437:Alcoholism / Q000453:epidemiology*; D000987:Antisocial Personality Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D002648:Child; D015897:Comorbidity; D003710:Demography; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D013287:Illicit Drugs; D008297:Male; D012114:Residential Treatment; D012720:Severity of Illness Index; D035781:Siblings; D019966:Substance-Related Disorders / Q000453:epidemiology* / Q000209:etiology / Q000534:rehabilitation
chemical_list: D013287:Illicit Drugs