Social phobia and avoidant personality disorder as related to parental history of social anxiety: a general population study.

Using a validated and DSM-IV compatible questionnaire, the present study related family history of excessive social anxiety to social phobia and avoidant personality disorder (APD) in epidemiologically identified probands in the general population. Probands met diagnostic criteria for social phobia with or without APD and APD with or without social phobia. A two- to three-fold increased relative risk of social anxiety was observed for all diagnostic groups. Increasing severity in probands by varying diagnostic criteria did not affect the relative risk. Because familial aggregation of social anxiety was not modulated by Axis I or II diagnosis or diagnostic cut-off levels, data imply that social phobia and APD may represent a dimension of social anxiety rather than separate disorders. Thus, having an affected family member is associated with a two- to three-fold risk increase for both social phobia and APD.