Axis II Comorbidity of Substance Use Disorders Among Patients Referred for Treatment of Personality Disorders

OBJECTIVE: The purpose of this study was to determine the extent of comorbid substance use disorders in patients referred for treatment of personality disorders. METHOD: Two hundred inpatients and outpatients were assessed by semistructured interviews for substance use and personality disorders. Univariate odds ratios were calculated for groups of substance use disorders and each DSM-III-R axis II disorder; comorbidity among axis II disorders was controlled in multivariate models predicting current or lifetime substance use disorder groups. The impact of personality disorder on chronicity and overall impairment associated with substance use disorders was evaluated. RESULTS: Close to 60% of subjects with substance use disorders had personality disorders. Borderline personality disorder was significantly associated with current substance use disorders, excluding alcohol and cannabis, and with lifetime alcohol, stimulant, and other substance use disorders, excluding cannabis. Antisocial personality disorder was associated with lifetime substance use disorders other than alcohol, cannabis, and stimulants. These relationships remained significant after controlling for the presence of all other personality disorders. There was no evidence that personality disorders increased the chronicity of substance use disorders, but comorbid personality disorders were associated with greater global impairment. CONCLUSIONS: Borderline personality disorder may be associated with a wide variety of substance use disorders, especially among patients seeking treatment for personality problems.