Background: The population prevalence of DSM-IV personality disorders (PDs) remains largely unknown. Data are reported here on the prevalence and correlates of clinician-diagnosed Clusters A, B, and C DSM-IV PDs in the general population of the United States.
Methods: Personality disorder screening questions from the International Personality Disorder Examination (IPDE) were administered in Part II (n = 5692) of the National Comorbidity Survey Replication (NCS-R). A probability sub-sample was then interviewed with the IPDE and used to link screening question responses with IPDE clinical diagnoses. The method of Multiple Imputation (MI) was then implemented to estimate prevalence and correlates of PDs in the full sample.
Results: The MI prevalence estimates were 5.7% Cluster A, 1.5% Cluster B, 6.0% Cluster C, and 9.1% any PD. All three PD clusters were significantly comorbid with a wide range of DSM-IV Axis I disorders. Significant associations of PDs with functional impairment were largely accounted for by Axis I comorbidity.
Conclusions: Strong Axis I comorbidity raises questions about the somewhat arbitrary separation of PDs from Axis I disorders in the DSM nomenclature. The impairment findings suggest that the main public health significance of PDs lies in their effects on Axis I disorders rather than in their effects on functioning.