• We examined the family histories of 68 agoraphobic patients, 35 subjects with miscellaneous-specific phobias, and ten subjects with social phobias. Of the 68 agoraphobic subjects, 26 had a positive family history of affective disorder based on our criteria. Five of the subjects with miscellaneous-specific phobias and none of the social phobic subjects had positive family histories of affective disorder. The difference between these categories is statistically significant. Family history of alcoholism was found to occur significantly more frequently in the agoraphobic vs the miscellaneous-specific phobic group, but not when compared with the social phobic group. A subpopulation in each phobic category was examined for past or present personal depressive illness, but no statistical difference was found. The increased incidence of affective disorder in firstdegree relatives distinguishes agoraphobia from other phobic disorders.