The findings summarized in this article suggest a genetic relationship between depression and alcohol dependence in some families where both disorders are transmitted. This conclusion is consistent with the idea that depression can be caused by many different genes (i.e., is a genetically heterogeneous condition). The results obtained so far have no direct implications for the treatment of patients with depression and/or alcohol dependence. However, they do reinforce the idea that some heavy drinkers may have genetic vulnerability to depression, as well as the observation that treatment of depressed alcoholic patients with antidepressants has generally had beneficial effects on the depression, and sometimes on the drinking as well (McGrath et al. 2000). In the future, genetic studies are likely to contribute to clinical treatment by identifying specific genes and their biochemical pathways, which could result in new therapeutic options for patient subgroups.
