title: Genetic and environmental risk factors in the aetiology of illicit drug initiation and subsequent misuse in women.
abstract: BACKGROUND
  Subsequent to initial exposure to the use of a psychoactive substance, psychoactive substance use disorder (PSUD) may or may not develop.
  
  
  OBJECTIVE
  To investigate the relationship between the risk factors for initiation and the subsequent misuse of psychoactive substances.
  
  
  METHODS
  The lifetime history of illicit substance use and misuse was obtained by telephone interview with 1934 members of female-female twin pairs. We apply a novel model, which estimates the role of genetic and environmental risk factors that influence initiation and those specific to misuse, to three classes of illicit psychoactive substances.
  
  
  RESULTS
  The individual-specific environment and family environment influenced the probability of initiation, but only individual-specific environment had an impact on the probability of subsequent misuse. Genetic factors which influence the risk of initiation and of misuse were identified.
  
  
  CONCLUSIONS
  Aetiological factors that influence drug initiation and subsequent misuse are correlated but not identical. Family environment is an important determinant of risk for drug experimentation. Two classes of genetic risk factors act on the liability to PSUD: those that influence the probability of initiation and those that influence the risk of misuse.
authors.affiliation: Department of Psychiatry, Virginia Institute for Psychiatric and Behavioral Genetics, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298-0126, USA.
authors.forename: K S
authors.initials: KS
authors.lastname: Kendler
authors.forename: L M
authors.initials: LM
authors.lastname: Karkowski
authors.forename: L A
authors.initials: LA
authors.lastname: Corey
authors.forename: C A
authors.initials: CA
authors.lastname: Prescott
authors.forename: M C
authors.initials: MC
authors.lastname: Neale
mesh_terms: D000328:Adult; D004200:Diseases in Twins; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D011619:Psychotropic Drugs; D012307:Risk Factors; D012650:Self Disclosure; D012931:Social Environment; D019966:Substance-Related Disorders / Q000209:etiology*; D011795:Surveys and Questionnaires
chemical_list: D011619:Psychotropic Drugs