Objective: Although studies have suggested that comorbid medical illness can affect the outcome of patients with depression, little is known about whether medical illness comorbidity affects treatment outcome in patients with anxiety.
Method: Primary care patients with panic disorder (n=232), participating in a randomized collaborative care intervention of CBT and pharmacology, were divided into those above (n=125) and below (n=107) the median for burden of chronic medical illness and assessed at 3, 6, 9 and 12 months.
Results: Subjects with a greater burden of medical illness were more psychiatrically ill at baseline, with greater anxiety symptom severity, greater disability and more psychiatric comorbidity. The intervention produced significant and similar increases in amount of evidence-based care, and reductions in clinical symptoms and disability that were comparable in the more and less medically ill groups.
Conclusions: The comparable response of individuals with more severe medical illness suggests that CBT and pharmacotherapy for panic disorder work equally well regardless of medical illness comorbidity. However, the more severe psychiatric illness both at baseline and follow-up in these same individuals suggest that treatment programs may need to be extended in time to optimize treatment outcome.