GENDER-SPECIFIC ETIOLOGIC DIFFERENCES IN ALCOHOL AND DRUG PROBLEMS - A BEHAVIORAL GENETIC-ANALYSIS

Although gender differences in the consumption and abuse of alcohol an d drugs are frequently reported, the etiology of these differences has received limited attention. The present study applied biometric genet ic analyses to determine whether self-report questionnaire items asses sing problem alcohol and drug we are influenced by gender-specific gen etic and environmental influences. The sample consisted of 693 volunte er general population twin pairs (209 monozygotic female, 138 monozygo tic male, 170 dizygotic female, 82 dizygotic male, 94 dizygotic opposi te-sex twin pairs). Heritability analyses showed that most aspects of drug and alcohol problems were differentially heritable by gender. Sig nificant additive genetic effects were found only in males, whereas in females, most substance we problems were wholly determined by environ mental factors. In both genders, non-shared environmental factors acco unted for the largest proportion of the variance, and further gender-b y-genotype analyses showed that these influences were not gender speci fic, but rather were common to males and females. Some preliminary evi dence teas also obtained that the we of illicit drugs may be etiologic ally distinct from the we of licit drugs in females and males.