Clinical and psychobiological characteristics of simultaneous panic disorder and major depression.

Simultaneous major depression and panic disorder appears to be a common occurrence in psychiatric patients. Patients with this condition present with more severe symptoms than patients with major depression only, respond less well to conventional antidepressants, and in general exhibit greater psychopathology over the course of their illness. Evidence suggesting a possible "dual diathesis," depression and panic, in these patients is reviewed from epidemiological, clinical, and biological perspectives. The importance of taking into account the combined symptoms in treatment planning and physiopathological studies is discussed.