Co-Occurring Bipolar and Substance Use Disorders: A Review of Impacts, Biopsychosocial Mechanisms, Assessment, and Treatment.

Individuals with bipolar disorder are at significant risk for having a co-occurring substance use disorder-particularly, alcohol and cannabis use disorders. Having a co-occurring substance use disorder is associated with a more pernicious clinical course, lower quality of life, and poorer treatment outcomes. Despite its increased morbidity, there is little research and clinical evidence-based guidelines on the treatment of individuals with co-occurring bipolar and substance use disorders. This review details current knowledge on the prevalence, clinical correlates, and biopsychosocial mechanisms underlying co-occurring bipolar and substance use disorders. The authors present recent research that highlights underlying mechanisms of comorbidity, including aberrant reward processing, stress sensitization, early childhood maltreatment, and gene-environment interactions. Next, the authors review current evidence-based recommendations for the assessment and treatment of co-occurring bipolar and substance use disorder, highlighting areas of needed future clinical research.