FAMILIAL INFLUENCES ON GAMBLING BEHAVIOR - AN ANALYSIS OF 3359 TWIN PAIRS

Background. Pathological gambling is becoming an increasing problem in the United States as the number of legalized gambling establishments grows. To examine vulnerability to pathological gambling, we estimated the familial contributions (i.e. inherited factors and/or experiences shared by twin siblings during childhood) to DSM-III-R pathological g ambling symptoms and disorder. Methods. Data were obtained from a tele phone interview performed in 1991-92 utilizing the Diagnostic Intervie w Schedule Version III-Revised. Interviews were administered to 6718 m embers of the nationally distributed Vietnam Era Twin Registry of male -male monozygotic and dizygotic twin pairs who served in the military during the Vietnam era. Results. Inherited factors explain between 35% (95% CI: 28% 42%) and 54% (95% CI 39%, 67%) of the liability for the five individual symptoms of pathological gambling behavior that could be estimated statistically. In addition, familial factors explain 56% (95% CI: 36%, 71%) of the,report of three or more symptoms of patholog ical gambling, and 62% (95% CI: 40%, 79%) of the diagnosis of patholog ical gambling disorder (four or more symptoms). Conclusions. Familial factors have an important influence on risk for pathological gambling behavior. The increasing access To legalized gambling is likely to res ult in a higher prevalence of Pathological gambling behavior among ind ividuals who are more vulnerable because of familial factors.