Clinical specificities of patients with substance use disorder and comorbid borderline personality disorder compared to patients with substance use disorder only: a retrospective study.

Introduction: Substance use disorder (SUD) is a common condition often associated with borderline personality disorder (BPD), and patients with both disorders (SUD + BPD) have more complex presentations and poorer outcomes in treatment. Thus, there is a need to identify more clearly the clinical differences between patients with SUD + BPD and those with SUD only to help clinicians in their diagnostic process.

Methods: Data from medical files of 92 patients with SUD (SUD only: n = 42; SUD + BPD: n = 50) treated in an outpatient psychiatry and addiction treatment center were extracted to compare the differences in terms of sociodemographic characteristics, substance used, psychopathological dimensions, comorbidity prevalence, and functional impairment.

Results: Compared to the SUD only group, patients in the SUD + BPD group were younger, more disabled, and less satisfied with their social life. Regarding substance used, the comorbid group had more frequently cannabis use disorder and poly nonalcoholic SUD. Regarding psychopathological dimensions, the comorbid group had higher levels of impulsivity, emotion regulation difficulties and alexithymia. Finally, regarding comorbidities, the comorbid group had a higher risk of comorbid anxiety, obsessive-compulsive, and post-traumatic stress disorders.

Conclusion: While being only exploratory, these results add evidence on the impact of the BPD comorbidity in patients with SUD and underline important dimensions that should be considered by clinicians working with this population.