[Mitral valve prolapse syndrome as an etiologic factor of anxiety disorder].

To assess whether a certain somatic disease is involved in the etiology of anxiety disorder, we examined the relationship between anxiety disorder and mitral valve prolapse syndrome (MVP). Patients with anxiety disorder were diagnosed according to the criteria of the American Psychiatric Association (Quick Reference to the Diagnostic Criteria from DSM-III). Two-dimensional echocardiography was carried out on 36 normal controls (15 males and 21 females) and 39 patients with anxiety disorder (19 males and 20 females); including 21 patients with panic disorder, 12 with generalized anxiety disorder, and 6 with atypical anxiety disorder. The echocardiograms were evaluated by a cardiologist unaware of clinical background about these patients. The presence of MVP was diagnosed according to the criteria by Yoshikawa, et al. or Nagata, et al. Findings of MVP were seen in 18 (46.1%) of the patients and 5 (13.9%) of the controls indicating a significantly higher incidence (chi 2 = 7.711, p less than 0.01) in the patients. In the patient subgroups, 14 patients with panic disorder (66.6%) and 4 with generalized anxiety disorder (33.3%) had MVP, showing a significantly higher incidence in the former (chi 2 = 14.335, p less than 0.01) than in the normal controls, but no statistical significance in the latter. No MVP was found in the patients with atypical anxiety disorder. These results suggest that some somatic diseases such as MVP may play a role in the etiology of anxiety disorder, especially panic disorder.