A population-based twin study of generalized anxiety disorder in men and women

This study aimed to a) assess whether genetic or environmental effects are of similar magnitude in the etiology of GAD in men and women, and b) invest igate whether familial (genetic or common environmental) risk factors are t he same in men and women, or whether there are gender-specific effects. We obtained a lifetime history of DSM-IIII-R GAD, via face-to-face and telepho ne interviews, from 3100 complete male-male, female-female, and male-female twin pairs, ascertained through a population-based registry. Biometrical t win modeling was utilized to estimate the relative contributions of genetic and environmental factors to liability for GAD, allowing for gender-specif ic effects. The familial aggregation of GAD in this sample was only modest. In the best-fitting models, the heritability of GAD was the same in men an d women, estimated at about 15% to 20%, with no effects of gender-specific genes detected.