Genetic analysis of diagnostic systems of alcoholism in males

Background: Research into genes involved in alcoholism could benefit from use of diagnostic systems most sensitive to detecting genetic influences. In this study, heritable influences were estimated in a single twin sample with commonly used criteria for alcoholism. Methods: Male twin probands ascertained through alcohol and drug abuse treatment programs and their same-sex cotwins (54 monozygotic and 65 dizygotic pairs) were diagnosed independently by DSM-III (alcohol dependence and alcohol abuse and/or dependence), Feighner (probable and definite alcoholism), and Cloninger (type 1 and type 2 alcoholism) systems. Using univariate structural equation modeling, heritability was estimated for each diagnostic system. Results: The highest heritability estimates were obtained for Feighner probable alcoholism (h2 = .63), Cloninger type 2 alcoholism (h2 = .54), and DSM-III alcohol dependence (h2 = .52). Conclusions: Certain diagnostic systems appear to have greater sensitivity for detecting genetic influence and may therefore be more appropriate for use in molecular genetic studies attempting to find genes for alcoholism.