Prevalence of Axis II Comorbidity in Bipolar Patients with and Without Alcohol Use Disorders

Objective: This study sought to determine the prevalence of comorbid personality disorder in euthymic bipolar I patients. Method: Sixty-one outpatients were assessed using the Structured Clinical Interview for DSM-III-R Personality Disorders (SCID II) and/or the Personality Diagnostic Questionnaire-Revised (PDQ-R). Results: Thirty-eight percent of bipolar patients met criteria for an Axis II diagnosis based on the SCID II. Bipolar subjects with a history of comorbid alcohol use disorder were significantly more likely to have a SCID II diagnosis (52%) compared to those bipolar subjects without an alcohol use disorder history (24%). Cluster A diagnoses were significantly more common in the bipolar/alcohol use disorder group. The PDQ-R consistently overdiagnosed Axis II disorders, finding 62% of the overall bipolar group to have an Axis II diagnosis. Conclusions: Euthymic bipolar patients may have an increased rate of personality disorders, but much less so than previously reported in studies that did not take into account (1) current mood state, (2) comorbidity for an alcohol use disorder, and (3) instrument used for assessment of Axis II psychopathology.