Is the comorbidity between social phobia and panic disorder due to familial cotransmission or other factors?

Background: We previously reported significantly elevated rates of social phobia in relatives of probands with panic disorder compared with relatives of other proband groups. This study further investigates the relationship between social phobia and panic disorder.

Method: This sample is from a family study that included 193 probands from four mutually exclusive groups (patients with panic disorder, patients with panic disorder and major depression, patients with early-onset major depression, and normal controls) and 1047 of their adult first-degree relatives. Best-estimate diagnoses were completed using DSM-III-R criteria.

Results: Social phobia and agoraphobia aggregate in the families of probands with panic disorder without major depression. Social phobia frequently co-occurs with panic disorder in relatives, but the risk for comorbidity does not vary across proband groups.

Conclusions: The familial aggregation of social phobia with panic disorder may be explained by the aggregation of panic disorder in relatives of probands with panic disorder combined with the tendency for panic disorder to occur comorbidly with social phobia in individuals.