The Severity of Personality Pathology: A Risk Factor for Concurrent Substance Use Disorders in Alcohol Use Disorder

Objective: Co-occurrence of substance use disorders (CO-substance use disorders) among individuals with alcohol use disorder (AUD) is largely recognized as a critical clinical issue. However, the specific clinical variables involved are still unclear. The recent findings are controversial in pointing out the unique contribution of both impulsivity and emotion dysregulation on CO-substance use disorders. Furthermore, the co-variation between AUD and other substance use disorders includes different aspects of maladaptive personality functioning (i.e., overall severity and specific features). Therefore, this study aims at clarifying the role of impulsivity, emotional dysregulation, and severity of personality pathology on CO-substance use disorders among treatment-seeking individuals with AUD. Methods: One hundred ninety-three treatment-seeking individuals with AUD (DSM-IV-TR) were consecutively recruited. Impulsivity (Barratt Impulsiveness Scale [BIS-11]), emotional dysregulation (Difficulties in Emotion Regulation Scale [DERS]), and personality pathology (Structured Clinical Interview for DSM-IV Axis II Personality Disorder [SCID-II]) were assessed after a 2-week detoxification period. The analyses were based on several stepwise forward logistic regressions. The total score of BIS-11 and DERS together with the number of SCID-II criteria were considered, in following the order, as independent variables controlling for the comorbidity with other lifetime Axis I disorders. CO-substance use disorders was the dependent variable (i.e., any CO-substance use disorders, benzodiazepine and cannabis/cocaine use disorders). Results: The number of SCID-II criteria was the only significant predictor of overall CO-substance use disorders, odds ratio (OR) = 1.16; 95% confidence interval (CI) [1.07, 1.26], p < .01, and cannabis/cocaine use disorders, OR = 1.19; 95% CI [1.08, 1.31], p < .01. On the contrary, DERS total score was the most robust predictor of benzodiazepine use disorder, OR = 1.02; 95% CI [1.01, 1.04], p < .01, albeit the severity of maladaptive personality functioning was also significantly associated with this disorder, OR = 1.09; 95% CI [1.00, 1.18], p < .05. Conclusions: The severity of maladaptive personality pathology represents one of the main aspects involved in CO-substance use disorders among individuals with AUD. This dimension predicts the CO-substance use disorders above and beyond specific personality dimensions and other psychiatric conditions. Therefore, personality functioning should be precisely assessed and personality pathology should be addressed in the framework of AUD treatments for promoting effective long-term outcomes.