Sex, stressful life events, and adult onset depression and alcohol dependence: are men and women equally vulnerable?

Higher rates of major depression (MD) among females, and of alcohol dependence (AD) among males, are among the most routinely reported findings in psychiatric epidemiology. One of the most often pursued explanations for sex differences in both disorders suggests that males and females have a differential vulnerability to stressors, which is manifested in sex-specific ways (MD for females, AD for males). However, existing evidence in support of this explanation is mixed. In the present study, we investigated sex differences in the association between stressful life events and MD and AD in a large national sample of adults in the United States (n = 32,744) using a prospective design. Logistic regression was used to estimate associations between stressful life events and both MD and AD; sex-specific effects of stress on MD and AD were evaluated by testing interaction terms between sex and stressors in the prediction of both outcomes. The number of stressful life events was predictive of first onset MD and AD. This was true for both males and females, and sex-by-stress interaction terms did not support the hypothesis that sex-specific responses to stressful life events lead to sex differences in first onset of MD and AD among adults. These results indicate the resistance of sex differences in MD and AD to simple explanations, and suggest the need for more nuanced models that incorporate both physiological and social aspects of vulnerability.