Clinical subtypes in panic disorder: their descriptive and prospective validity.

In a sample of 97 patients with panic attacks, presence of agoraphobia was associated with a more severe syndrome of panic anxiety both at index assessment and during one-year follow-up but was not associated with increased incidence of major depression. Groups with a history of depression--primary or secondary to the onset of panic--did not differ from the group without depression when severity of anxiety was concerned but were more severely impaired and had a higher incidence of further depressive episodes during follow-up. For future classification of panic disorder, subtypes defined according to associated syndromes of agoraphobia or depression are proposed, since these conditions appear constant through follow-up.