The goal of this review is to present an overview of the genetic epidemiology of substance use and misuse in adolescents. However, the study of genetic and environmental influences is predicated on an accurate understanding of the behavior being studied. As with all behavioral or psychiatric disorders there is considerable need both for precise definition and assessment of these behaviors9 and to place them within a broader developmental framework.10 Specific issues that need to be considered include: a) Reliance on self report. Although self–reports may underestimate the true extent of substance use, they are generally accepted as reliable and valid indicators of substance use.11 Unlike some other areas of child and adolescent psychiatry where parental or other collateral reports are recognized as highly informative, parental reports of their child’s substance use may be less reliable and valid as adolescents actively try to conceal the extent of their substance use from parents. While the use of biological samples (e.g., urine tests) may be ill suited for assessing lifetime patterns of substance use, they are recognized as useful in clinic referred samples
