Differentiating the mood and anxiety disorders: a quadripartite model.

Recent work has focused on explicating the relations among the current mood and anxiety disorders. This research has yielded some important findings (e.g., the very strong link between generalized anxiety disorder and the unipolar mood disorders). I discuss problems associated with disorder-based analyses, however, and I argue that they need to be supplemented by examining relations among the specific symptom dimensions within these diagnostic classes. I demonstrate that two quantitative elements need to be considered when analyzing the properties of symptoms-the level of specificity and the magnitude of the general distress variance. These quantitative elements can be used to organize relevant symptoms into four groups (i.e., a quadripartite model) that reflect varying combinations of distress and specificity. I illustrate the value of this approach by reviewing the properties of the major symptom dimensions within posttraumatic stress disorder, obsessive-compulsive disorder, and major depression.