PDQ-R personality disorders in bipolar patients

The prevalence of personality traits and disorders in bipolar patients as reported in the literature varies widely. The Personality Diagnostic Questionnaire-Revised (PDQ-R) is a self-report instrument for DSM-IIIR personality disorders found to have validity, but with high sensitivity and moderate specificity. This study was designed to assess personality disorders in bipolar patients using the PDQ-R. Fifty bipolar patients in a long-term lithium treatment program completed the PDQ-R. Over one half the patients (58%) scored for one or more personality disorders. A total of 71 diagnoses was made among the 50 patients, or a mean of 1.42 per patient. The majority of the axis II diagnoses were from cluster B, with borderline the most prevalent, followed by histrionic. The PDQ-R has high sensitivity but moderate specificity and may overdiagnose personality disorders in bipolar patients. The PDQ-R may register subclinical aspects of affective disorder as personality.