Hypochondriasis and panic disorder. Boundary and overlap.

BACKGROUND

To determine the nosological and phenomenological overlap and boundaries between panic disorder and hypochondriasis, we compared the symptoms, disability, comorbidity, and medical care of primary care patients with each diagnosis.

METHODS

Patients with DSM-III-R panic disorder were recruited by screening consecutive primary care clinic attenders and then administering a structured diagnostic interview for panic disorder. Patients also completed self-report questionnaires, and their primary care physicians completed questionnaires about them. They were then compared with patients with DSM-III-R hypochondriasis from the same setting who had been studied previously.

RESULTS

One thousand six hundred thirty-four patients were screened; 135 (71.0% of the 190 eligible patients) completed the research battery; 100 met lifetime panic disorder criteria. Twenty-five of these had comorbid hypochondriasis. Those without comorbid hypochondriasis (n = 75) were then compared with patients with hypochondriasis without comorbid panic disorder (n = 51). Patients with panic disorder were less hypochondriacal (P < .001), somatized less (P < .05), were less disabled (P < .001), were more satisfied with their medical care (P < .001), and were rated by their physicians as less help rejecting (P < .05) and less demanding (P < .01). Major depression was more prevalent in the group with panic disorder (66.7% vs 45.1%; P < .05), as were phobias (76.0% vs 37.3%; P < .001), but somatization disorder symptoms (P < .0001) and generalized anxiety disorder were less prevalent (74.5% vs 16.0%; P < .001) in panic disorder than was hypochondriasis.

CONCLUSIONS

While hypochondriasis and panic disorder co-occur to some extent in a primary care population, the overlap is by no means complete. These patients are phenomenologically and functionally differentiable and distinct and are viewed differently by their primary care physicians.