Clinical outcome data of anxiety patients treated with cannabis-based medicinal products in the United Kingdom: a cohort study from the UK Medical Cannabis Registry

RATIONALE: Cannabis-based medicinal products (CBMPs) have been identified as novel therapeutics for generalised anxiety disorder (GAD) based on pre-clinical models; however, there is a paucity of high-quality evidence on their effectiveness and safety. OBJECTIVES: This study aimed to evaluate the clinical outcomes of patients with GAD treated with dried flower, oil-based preparations, or a combination of both CBMPs. METHODS: A prospective cohort study of patients with GAD (n = 302) enrolled in the UK Medical Cannabis Registry prescribed oil or flower-based CBMPs was performed. Primary outcomes were changes in generalised anxiety disorder-7 (GAD-7) questionnaires at 1, 3, and 6 months compared to baseline. Secondary outcomes were single-item sleep quality scale (SQS) and health-related quality of life index (EQ-5D-5L) questionnaires at the same time points. These changes were assessed by paired t-tests. Adverse events were assessed in line with CTCAE (Common Terminology Criteria for Adverse Events) v4.0. RESULTS: Improvements in anxiety, sleep quality and quality of life were observed at each time point (p < 0.001). Patients receiving CBMPs had improvements in GAD-7 at all time points (1 month: difference −5.3 (95% CI −4.6 to −6.1), 3 months: difference −5.5 (95% CI −4.7 to −6.4), 6 months: difference −4.5 (95% CI −3.2 to −5.7)). Thirty-nine participants (12.9%) reported 269 adverse events in the follow-up period. CONCLUSIONS: Prescription of CBMPs in those with GAD is associated with clinically significant improvements in anxiety with an acceptable safety profile in a real-world setting. Randomised trials are required as a next step to investigate the efficacy of CBMPs.