Psychiatric disorders in patients with unexplained syncope or presyncope have received little attention in the recent medical literature. Seventy-two patients with unexplained syncope and presyncope referred to the Duke Syncope Clinic received a standardized evaluation. Symptoms appeared to be explained by a psychiatric diagnosis in 17(24%) patients (panic disorder in 13%, and major depression in 11%). These patients were younger than other patients with syncope and presyncope (p < .001) and had more disability due to their syncope and presyncope (p < .0l). They also had more frequent episodes of syncope (p < .005) and more symptoms as a part of their prodrome (p < .0001). Treatment aimed at the psychiatric diagnosis resulted in a remission from syncopal or presyncopal symptoms in 90% of patients who complied with therapy. The authors conclude that psychiatric disorders are common in patients with syncope and presyncope, that certain characteristics of the patient and prodrome may alert physicians to a psychiatric diagnosis, and that directed treatment may result in relief from symptoms.