Comorbidity of Personality Disorder among Substance Use Disorder Patients: A Narrative Review

Comorbidity of personality disorders (PDs) and substance use disorders (SUDs) is common in clinical practice. Borderline PD and antisocial PD are particularly found to be associated with SUDs. Our review suggests that the overall prevalence of PD ranges from 10% to 14.8% in the normal population and from 34.8% to 73.0% in patients treated for addictions. Even though the types of PD seen in patients with drug and alcohol use disorder are similar, the prevalence of any PD is higher among patients with drug use disorder than alcohol use disorder. The higher comorbidity between these two conditions has been explained by a primary personality pathology followed by a secondary development of a SUD. The comorbidity with PD positively correlates with the severity of the SUD. Comorbid PD among patients with SUDs is a predictor of poor prognosis in terms of poorer treatment response and outcome. Psychotherapy is the mainstay of treatment in comorbid condition with dialectical behavioral therapy, dynamic deconstructive psychotherapy, and dual-focused schema therapy having the most evidence base. Pharmacotherapy is primarily indicated for the acute crisis management or for the treatment of other comorbid conditions such as psychosis and depression. However, the evidence is insufficient as of now to suggest one treatment over the other. Further research is required to identify more efficacious treatment approaches for this comorbidity.