use disorder for illicit drugs?

The use of DSM criteria to evaluate liability to substance use disorders (SUDs) and to identify SUD phenotypes may not provide the sensitivity required to identify genes associated with vulnerability to SUDs. The purpose of this study is to evaluate a number of basic aspects of substance use that may be more proximal than full SUDs to risk genes, some of which may thus have greater potential utility as phenotypes in subsequent molecular genetic analyses. In this paper we present results from the first stage of our planned analyses, focusing on how individual symptoms of abuse and dependence may be used to create alternate phenotypes for SUDs. Specifically, we used factor analysis and biometrical modeling on each symptom of illicit substance abuse and dependence within different types of substances, and compared and contrasted factor patterns and heritabilities across the different0306-4603/ $