title: General and specific predictors of nicotine and alcohol dependence in early adulthood: genetic and environmental influences.
abstract: OBJECTIVE
  This study builds on previous work delineating a hierarchical model of family environmental risk in relation to a hierarchical model of externalizing disorders (EXTs) by evaluating for gene-environment interplay in these relationships. The associations between parent-child relationship quality (conflict, bonding, and management) and substance-specific adolescent family environments (parental/sibling tobacco/alcohol use) in relation to young adult EXTs (age ∼22 years nicotine, alcohol, and other drug dependence; antisocial and risky sexual behavior) were evaluated.
  
  
  METHODS
  The sample included 533 adopted offspring and 323 biological offspring. Because adopted youth do not share genes with their parents, a significant association between parent-child relationship quality and EXTs would provide evidence against passive gene-environment correlation (rGE). Significant associations between parental tobacco/alcohol use in relation to offspring nicotine/alcohol dependence in the adopted offspring support common environmental influence. Significant associations detected for the biological offspring only suggest common genetic influence.
  
  
  RESULTS
  For both adoptive and biological offspring, there was a significant association between parent-child relationship quality and EXTs. Parental tobacco/alcohol use was unrelated to EXTs. Sibling tobacco/alcohol use was related to EXTs, but only for the biological siblings. Parental tobacco use was associated with the residual variance in nicotine dependence in adopted offspring.
  
  
  CONCLUSIONS
  Findings replicate a long-term influence of adolescent parent-child relationship quality on adult EXTs. Findings extend previous research by providing evidence against passive rGE in this association. The association between parental tobacco use and adult nicotine dependence appears to be environmentally mediated, but caution is warranted as we found this relationship only for adopted youth.
authors.affiliation: Department of Psychology, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Diana R
authors.initials: DR
authors.lastname: Samek
authors.affiliation: Department of Psychology, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Keyes
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, Michigan.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Hicks
authors.affiliation: Social Development Research Group, University of Washington, Seattle, Washington.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bailey
authors.affiliation: Department of Psychology, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Matt
authors.initials: M
authors.lastname: McGue
authors.affiliation: Department of Psychology, University of Minnesota, Minneapolis, Minnesota.
authors.forename: William G
authors.initials: WG
authors.lastname: Iacono
mesh_terms: D000293:Adolescent; D000300:Adoption; D000428:Alcohol Drinking / Q000453:epidemiology* / Q000235:genetics; D000437:Alcoholism / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D005192:Family Health; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010287:Parent-Child Relations; D010290:Parents; D012307:Risk Factors; D012309:Risk-Taking; D012725:Sexual Behavior; D035781:Siblings; D014029:Tobacco Use Disorder / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D055815:Young Adult