Comorbid depression, but not comorbid anxiety disorders, predicts poor outcome in anxiety disorders

Influence of type of comorbidity was studied over the course of 1 year in a sample of 141 outpatients with panic disorder with or without agoraphobia and generalized anxiety disorder, who were receiving different forms of cognitive behavior therapy. Influence of type of comorbidity was determined on the basis of change scores (linear regression analysis) and remission data (Kaplan-Meier survival analysis). Three categories, as assessed at baseline, were compared: no comorbidity, comorbidity among anxiety disorders, and comorbidity with mood disorders. Primary outcome variable: State-Trait Anxiety Inventory State subscale measured at four assessments (0, 12, 24, and 52 weeks). Analyses of change and remission indicated that comorbidity with mood disorders led to (i) less improvement and (ii) a lower remission rate than comorbidity among anxiety disorders and no comorbidity. Because comorbidity has a critical influence on prognosis, it seems to be important to make a reliable diagnosis of the disorders present.