Twenty patients with myasthenia gravis and 15 patients with polymyositis/dermatomyositis were assessed with a structured interview. Fifteen patients (43%) were diagnosed with an anxiety disorder. Significantly more myasthenic patients (40%) than polymyositis/dermatomyositis patients (7%) were diagnosed with panic disorder/agoraphobia. These findings suggest that the symptoms of myasthenia gravis may predispose vulnerable individuals to panic disorder/agoraphobia.
