Prevalence of cannabis use disorder among individuals using medical cannabis at admission to inpatient treatment for substance use disorders

INTRODUCTION: Cannabis is used for medical and recreational purposes and may result in cannabis use disorder (CUD). This study explored the prevalence of cannabis use disorder and other psychiatric comorbidities among inpatients undergoing treatment for substance use disorder who reported medical cannabis use at admission. METHODS: We assessed CUD and other substance use disorders based on DSM-5 symptoms, anxiety with the Generalized Anxiety Disorder scale (GAD-7), depression with the Patient Health Questionnaire (PHQ-9), and post-traumatic stress disorder with the PTSD Checklist for DSM-5 (PCL-5). We compared the prevalence of CUD and other psychiatric comorbidities between inpatients who endorsed the use of cannabis for medical purposes only vs those endorsing use for medical and recreational purposes. RESULTS: Among 125 inpatients, 42% reported medical use only, and 58% reported medical and recreational use (dual motives). For CUD, 28% of Medical-Only and 51% of Dual-Use motives patients met the diagnostic criteria for CUD (p = 0.016). High psychiatric comorbidities were present: 79% and 81% screened positive for an anxiety disorder, 60% and 61% screened positive for depression, and 66% and 57% screened positive for PTSD for the Medical-Only and Dual-Use inpatients, respectively. CONCLUSIONS: Many treatment-seeking individuals with substance use disorder who report medical cannabis use meet criteria for CUD, particularly those reporting concurrent recreational use.