COMORBIDITY AS A FUNDAMENTAL FEATURE OF GENERALIZED ANXIETY DISORDERS- RESULTS FROM THE NATIONAL COMORBIDITY STUDY (NCS)

Generalized anxiety disorder (GAD) is a relatively common mental disor der in the general population, afflicting approximately 3% of communit y residents during their lifetime. It is not a benign condition, since significantly increased disability and dysfunction are found in GAD s ubjects compared to non-CAD subjects. For decades GAD has frequently b een observed in the context of other mental and substance abuse disord ers. Initially the weight of clinical opinion indicated that CAD was a residual disease which should only be diagnosed when other mental dis orders are not present. More recently there has been a growing recogni tion that comorbidity is a fundamental characteristic of the course an d nature of GAD. In a series of secondary analyses conducted in subjec ts in the National Comorbidity Study database, we found that 8 out of 10 subjects with lifetime GAD also had a comorbid mood disorder during their lifetime. We found unipolar disorders to be four times more com mon in GAD than bipolar disorders (67% vs. 17%), providing indirect su pport for the previously reported observation that GAD and major depre ssion may share a common genetic diathesis. In addition, our analyses support the conclusion that when comorbid mood disorders are present i n GAD, a significant increase in associated disability and dysfunction is also found. Thus this comorbid relationship has important implicat ions for clinical course and outcome.