A family study of anxiety neurosis. Morbidity risk in families of patients with and without mitral valve prolapse.

• It has been suggested that some patients with anxiety neurosis (panic disorder) may have the mitral valve prolapse syndrome (MVPS) that can produce symptoms frequently associated with panic attacks. Previous work on a group of 21 patients with anxiety neurosis supported this hypothesis by finding MVPS in eight patients. These patients provided a unique opportunity to study the families of anxiety neurosis patients with and without MVPS to learn whether the high familial morbidity risk in anxiety neurosis is related to the presence or absence of MVPS in the proband. We interviewed first-degree relatives in 19 kindreds with anxiety neurosis and 19 control kindreds finding a morbidity risk for panic disorder of 41% among interviewed relatives and 31% based on data from all sources. These risks were substantially higher than those found among the control relatives. Seven kindreds were indexed through panic disorder probands with MVPS and when their kindreds were compared with those of the 12 panic disorder probands without MVPS, the familial morbidity risk for anxiety neurosis was similar. The data indicate that the familial morbidity risk for panic disorder is as high as any in the psychiatric genetics literature. However, it is independent of a diagnosis of MVPS in the proband.