The COGA researchers first determined the prevalence of major depression and depressive syndrome in the families of the alcoholic probands (see table 2). These studies found that among both males and females, major depression was not more common in alcoholic participants than in nonalcoholic participants. However, depressive syndrome was significantly more common among male and female alcoholics than among nonalcoholics. As a result, the prevalence of the DEP phenotype (which combines both major depression and depressive syndrome) was increased in both alcoholic males and alcoholic females.
