Structure of the DSM-5 generalized anxiety disorder criteria among a large community sample of worriers

Abstract

Background: There is growing empirical and clinical consensus that many psychiatric disorders are continuous in nature. The DSM-5 however makes a categorical distinction between subthreshold and threshold cases of generalized anxiety disorder (GAD). This study tested the a priori assumption that the DSM-5 criteria identify a break in psychopathology between subthreshold and threshold cases of GAD. Methods: Respondents of the 2007 National Survey of Mental Health and Well Being who self-identified as worriers were selected for analyses (n=1738). The GAD criteria were assessed using the World Mental Health version of the Composite International Diagnostic Interview. Item response, latent class and factor mixture models were estimated to assess the structure of the GAD criteria. Results: The relative fit of the latent variable models suggested that a single continuous factor explains the way that worriers endorse the GAD criteria. However, the similar psychometric properties of the GAD criteria suggested that the GAD criteria impose a relatively finite threshold over this dimension of severity. Limitations: Although these structural analyses did not identify a break in psychopathology between subthreshold and threshold cases of GAD based on the way that respondents endorsed the DSM-5 criteria, it is possible that structural analyses of risk factors and other clinical correlates of GAD may identify such a break in the future. Conclusions: These data suggest that the DSM-5 GAD criteria lend themselves to making both categorical decisions about cases as well as being indices of a continuum of severity.