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.