Using a nationally representative sample, this study examines the disease-specific impairments of DSM-IV generalized anxiety disorder (GAD) by comparing them to the impairments associated with major depressive disorder (MDD). Results are based on 4181 respondents between the ages of 18-65 years who were interviewed with the 12-month version of the Munich-Composite International Diagnostic Interview as part of the German National Health Interview and Examination Survey-Mental Health Supplement (GHS). After controlling for age, gender, and other psychopathology, 'pure' current GAD without MDD (n = 33), pure MDD (n = 344) and comorbid GAD and MDD (n = 40) were each associated with high impairment as defined by poor self-perceived health, at least 3 days limited or impaired in the past month, and low quality of life scores [from the Short Form-36 Health Survey (SF-36)]. Quality of life scores on several of the SF-36 scales were significantly lower for respondents with pure GAD as compared to respondents with pure MDD. Overall, the results show that DSM-IV GAD is associated with high impairment even after controlling for other psychopathology. The impairment outcomes for GAD were comparable in size to those for MDD. These findings underline the significance of this disorder from a clinical and social perspective and provide support for the independent diagnostic status of GAD.