Familial aggregation of panic in nonclinical panickers.

Despite several methodological difficulties inherent in the nonclinical panic literature, some researchers have highlighted the consistent finding that a greater proportion of panickers than nonpanickers report a history of panic in first-order relatives to be supportive of the validity of nonclinical panic research findings. However, in all of these studies, familial aggregation differences have been evaluated via panickers' and nonpanickers' self-reports of familial panic history. Given evidence that questionnaire assessment of panic results in substantial false positives (Brown & Cash, 1989, Journal of Anxiety Disorders, 3, 139-148), it was hypothesized that familial aggregation differences could be largely attributable to this phenomenon as well. Consistent with this hypothesis, as in prior studies, a significantly greater proportion of panickers than nonpanickers reported first-order relatives who experienced panic; however, panickers and nonpanickers also differed in their reports of close male friends and close female friends who had experienced panic. On the basis of these data, potential caveats to prior conclusions concerning familial aggregation differences between nonclinical panickers and nonpanickers are discussed as are methodological considerations for future nonclinical panic research.