FAMILY STUDY OF PANIC DISORDER - COMPARISON WITH GENERALIZED ANXIETY DISORDER, MAJOR DEPRESSION AND NORMAL SUBJECTS

Family studies have demonstrated that genetic factors are involved in panic and other anxiety disorders. In order to investigate these factors, 25 probands with panic disorder (PD) were compared with three other groups (age and sex matched): patients with generalized anxiety disorder (GAD), major depressive disorder (MDD), and normal subjects. About 75% of all first-degree relatives were personally interviewed. Age-corrected morbidity risk (MR) was calculated according to the Stromgren method. The distribution of psychopathology in first-degree relatives showed significantly greater MR for PD in the relatives of PD probands in comparison with all groups. For all anxiety disorders and various psychiatric disorders, relatives of PD patients also showed greater MR than controls. The frequency of GAD and MDD in relatives did not discriminate between the groups. The results of this study validate PD as a separate illness from GAD, the differentiation of PD from MDD, and support the hypothesis of a genetic contribution to the predisposition of PD.