Component III: Longitudinal Adoption Study of Adolescent Substance Experimentation

This component is designed to assess genetic and environmental influences on experimentation with tobacco, alcohol, marijuana, and other drugs using a longitudinal adoption design. It builds on more than 20 years of data collected by the CAP (Colorado Adoption Project website), and focuses on the transmission of substance use and antecedent behaviors such as conduct disorder symptoms, other behavioral problems, and academic achievement difficulties.

Principal Investigator: Robin P. Corley
Co-Investigators: Susan Young , Gregory Carey

During the first five years of the center, beginning in 1997, we accomplished the following highlights for Component III:

  • Interviewed over 720 participants in the Colorado Adoption Project at least once, and 295 of them twice (in late adolescence and early adulthood).
  • Obtained 558 DNA samples from CAP subjects either by swabs or mouthwash and began candidate gene analyses using these samples.
  • In conjunction with twin and Component II family data, established the heritability of drug use, abuse, and symptoms of dependence from specific substances and for general vulnerability, contributing to the definition of a clinically valid, familial, and heritable Dependence Vulnerability phenotype for initial QTL analysis.
  • In conjunction with the longitudinal twin sample complimentary to CAP, established a dopamine related genetic association with an early indicator of behavioral disinhibition.
  • Associated that indicator of behavioral disinhibition (CBC Externalizing scores) to later substance experimentation in both boys and girls.
  • Identified acceptance of adoption as a potential protective factor against substance use in adolescence among adoptees.


component I component II component IV component V component VI

Division of Substance Dependence