Personality disorder and substance use disorder: an updated review

PURPOSE OF REVIEW: Personality disorder and substance use disorder (SUD) frequently co-exist and are associated with increased morbidity and all-cause mortality. This review summarizes the recent evidence on the epidemiology, shared pathogenesis, clinical course, assessment and management of personality disorder and SUD comorbidity. The findings aim to improve the understanding of this comorbidity, highlighting implications for clinical practice and future research. RECENT FINDINGS: Diagnostic practice has shifted from categorical to dimensional frameworks, with the introduction of the DSM-5 Alternative Model for Personality Disorders (AMPD), the International Classification of Disorders (ICD-11), and the Hierarchical Taxonomy of Psychopathology (HiTOP). Personality disorder and SUD share common genetic and neurobiological vulnerabilities that affect reward processing, executive control, and emotion regulation. Additionally, childhood adversities and certain personality dimensions (e.g. negative affectivity, disinhibition, and externalizing traits) are associated with a higher risk of this comorbidity. Recently, digital phenotyping and machine learning methods have been useful for better risk stratification and personalized care. Integrated personality-informed interventions have been found beneficial, with pharmacotherapy playing a supportive role. SUMMARY: Current evidence increasingly supports personality disorder and SUD as interconnected disorders, which may benefit from a unified approach towards assessment and management. Nevertheless, robust longitudinal and interventional studies are still needed to strengthen the evidence.