title: Heritability of smoking, alcohol use, and psychological characteristics among adolescent twins in Qingdao, China.
abstract: BACKGROUND
  Previous studies of genetic and environmental influences on adolescent substance use have been limited to Western samples.
  
  
  METHODS
  This study assesses genetic and environmental contributions to cigarette smoking, alcohol use, and psychological variables (depression, anxiety, aggression, hostility) among 602 pairs of adolescent twins, 11 to 19 years old, in Qingdao, China.
  
  
  RESULTS
  Heritable influences were more pronounced for alcohol use than cigarette smoking. In univariate analyses, no heritable effects were found for depression or aggression, and modest heritability was found for anxiety. Hostility was relatively more heritable in girls than boys. Bivariate associations between substance use and psychological measures could be attributed to a combination of common genetic and environmental factors.
  
  
  CONCLUSIONS
  Among Chinese adolescents, experimentation with tobacco is familial, and experimentation with alcohol is heritable. The genetic and environmental architecture of hostility differs by gender. Consistency of univariate results with Western adolescent samples appears limited to the alcohol use measures.
authors.affiliation: Claremont Graduate University, 180 E. Via Verde, San Dimas, CA 91773, USA. jenniferbethunger@gmail.com
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Unger
authors.forename: Christina N
authors.initials: CN
authors.lastname: Lessov-Schlaggar
authors.forename: Zengchang
authors.initials: Z
authors.lastname: Pang
authors.forename: Qian
authors.initials: Q
authors.lastname: Guo
authors.forename: Feng
authors.initials: F
authors.lastname: Ning
authors.forename: Peggy
authors.initials: P
authors.lastname: Gallaher
authors.forename: Liming
authors.initials: L
authors.lastname: Lee
authors.forename: Weihua
authors.initials: W
authors.lastname: Cao
authors.forename: David
authors.initials: D
authors.lastname: Conti
authors.forename: C Anderson
authors.initials: CA
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D000428:Alcohol Drinking / Q000453:epidemiology* / Q000235:genetics*; D002648:Child; D002669:Child Welfare; D002681:China / Q000453:epidemiology; D016001:Confidence Intervals; D005260:Female; D059647:Gene-Environment Interaction; D006293:Health Promotion; D006306:Health Surveys; D006801:Humans; D008297:Male; D011634:Public Health; D012907:Smoking / Q000453:epidemiology* / Q000235:genetics*; D014427:Twins / Q000523:psychology*