Objective: The purpose of this study was to assess whether joint hypermobility syndrome is more frequent in patients with panic disorder, agoraphobia, or both than in control subjects and, if so, to determine whether mitral valve prolapse modifies or accounts in part for the association.
Method: A case-control study was conducted in a general teaching hospital outpatient clinic. Subjects were 99 patients, newly diagnosed and untreated, with panic disorder, agoraphobia, or both and two groups of age- and sex-matched control subjects: 99 psychiatric patients and 64 medical patients who had never suffered from any anxiety disorder. Measures consisted of the Structured Clinical Interview for DSM-III-R, Beighton's criteria for joint hypermobility syndrome, and two-dimensional and M-mode echocardiogram. The presence of mitral valve prolapse and joint hypermobility syndrome was explored by raters who were blind to subjects' psychiatric status.
Results: Joint hypermobility syndrome was found in 67.7% of patients with anxiety disorder but in only 10.1% of psychiatric and 12.5% of medical control subjects. On the basis of statistical analysis, patients with anxiety disorder were over 16 times more likely than control subjects to have joint laxity. These findings were not altered after the presence of mitral valve prolapse was taken into account. Of the patients with anxiety disorder, those who had joint hypermobility syndrome were younger and more often women and had an earlier onset of the disorder than those without joint hypermobility syndrome.
Conclusions: Joint laxity is highly prevalent in patients with panic disorder, agoraphobia, or both and may reflect a constitutional disposition to suffer from anxiety. Mitral valve prolapse plays a secondary role in the association between joint hypermobility and anxiety.