title: Parental separation and early substance involvement: results from children of alcoholic and cannabis dependent twins.
abstract: BACKGROUND
  Risks associated with parental separation have received limited attention in research on children of parents with substance use disorders. We examined early substance involvement as a function of parental separation during childhood and parental alcohol and cannabis dependence.
  
  
  METHODS
  Data were drawn from 1318 adolescent offspring of monozygotic (MZ) or dizygotic (DZ) Australian twin parents. Cox proportional hazards regression analyses were conducted predicting age at first use of alcohol, first alcohol intoxication, first use and first regular use of cigarettes, and first use of cannabis, from parental separation and both parent and cotwin substance dependence. Parent and cotwin alcohol and cannabis dependence were initially modeled separately, with post hoc tests for equality of effects.
  
  
  RESULTS
  With few exceptions, risks associated with parental alcohol versus cannabis dependence could be equated, with results largely suggestive of genetic transmission of risk from parental substance (alcohol or cannabis) dependence broadly defined. Controlling for parental substance dependence, parental separation was a strong predictor for all substance use variables, especially through age 13.
  
  
  CONCLUSIONS
  Together, findings underscore the importance of parental separation as a risk-factor for early substance involvement over and above both genetic and environmental influences specific to parental alcohol and cannabis dependence.
authors.affiliation: Department of Counseling and Educational Psychology, Indiana University School of Education, Bloomington, IN, United States; Midwest Alcoholism Research Center, Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States. Electronic address: mwaldron@indiana.edu.
authors.forename: Mary
authors.initials: M
authors.lastname: Waldron
authors.affiliation: Midwest Alcoholism Research Center, Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Julia D
authors.initials: JD
authors.lastname: Grant
authors.affiliation: Midwest Alcoholism Research Center, Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Kathleen K
authors.initials: KK
authors.lastname: Bucholz
authors.affiliation: Addictions Department, Institute of Psychiatry, King's College, London, United Kingdom.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lynskey
authors.affiliation: Department of Psychology, University of Missouri, Columbia, MO, United States.
authors.forename: Wendy S
authors.initials: WS
authors.lastname: Slutske
authors.affiliation: Midwest Alcoholism Research Center, Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Anne L
authors.initials: AL
authors.lastname: Glowinski
authors.affiliation: Genetic Epidemiology Unit, Queensland Institute of Medical Research, Brisbane, Australia.
authors.forename: Anjali
authors.initials: A
authors.lastname: Henders
authors.affiliation: Faculty of Arts and Business, University of the Sunshine Coast, Queensland, Australia.
authors.forename: Dixie J
authors.initials: DJ
authors.lastname: Statham
authors.affiliation: Genetic Epidemiology Unit, Queensland Institute of Medical Research, Brisbane, Australia.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Martin
authors.affiliation: Midwest Alcoholism Research Center, Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Heath
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000437:Alcoholism / Q000175:diagnosis / Q000235:genetics / Q000523:psychology*; D002648:Child; D016241:Child of Impaired Parents / Q000523:psychology*; D015331:Cohort Studies; D004243:Divorce / Q000523:psychology* / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000175:diagnosis / Q000235:genetics / Q000523:psychology*; D012307:Risk Factors; D014427:Twins / Q000235:genetics / Q000523:psychology*
keywords: Adolescent substance use; Children of twins; Parental separation; Parental substance dependence