PSYCHIATRIC-DISORDERS IN RELATIVES OF PROBANDS WITH PANIC DISORDER AND OR MAJOR DEPRESSION/

Background: Panic disorder and major depression (MDD) are both highly familial disorders that co-occur in individuals but do not cosegregate in families. Evidence concerning their familial aggregation with othe r psychiatric disorders, including phobias, substance abuse, and antis ocial personality, has been contradictory. In part, the contradictory findings may be due to failure to account for the effects of proband c omorbidity on risks in relatives. Methods: A family study of 1047 adul t first-degree relatives of 193 probands in four diagnostic groups (pa nic disorder without MDD, panic disorder plus MDD, early-onset MDD, an d screened normal controls) was used to determine the range of psychia tric disorders associated with panic disorder and MDD and the effects of proband comorbidity on the rates of disorders in relatives. Results : Compared to relatives of normal controls, relatives of probands with panic disorder or panic disorder and MDD showed significantly increas ed risks of panic disorder, but relatives of probands with early-onset MDD did not. After proband comorbidity was controlled for, relatives of probands with panic disorder were also at a significantly increased risk for social phobia but not for any other psychiatric disorders. R elatives of probands with early-onset MDD were at significantly increa sed risks for MDD, dysthymia, abuse of or dependence on alcohol and ot her drugs, and antisocial personality disorders but not for any other psychiatric disorders. Conclusions: We conclude that panic disorder is a specific familial entity that is not associated with a broad range of other anxiety or other psychiatric disorders, with the possible exc eption of social phobia. Dysthymia, substance abuse, and antisocial pe rsonality appear to be on the spectrum of early-onset MDD.