Abstract
Background: Treatment resistance is a significant problem among young people experiencing moderate-to-severe anxiety, affecting nearly half of all patients. This study investigated the safety and efficacy of cannabidiol (CBD), a non-intoxicating component of Cannabis sativa, for anxiety disorders in young people who previously failed to respond to standard treatment. Methods: In this open-label trial, 31 young people aged 12-25 years with a DSM-5 anxiety disorder and no clinical improvement despite treatment with cognitive-behavioral therapy and/or antidepressant medication were enrolled between May 16, 2018, and June 28, 2019. All participants received add-on CBD for 12 weeks on a fixed-flexible schedule titrated up to 800 mg/d. The primary outcome was improvement in anxiety severity, measured with the Overall Anxiety Severity and Impairment Scale (OASIS), at week 12. Secondary outcomes included comorbid depressive symptoms, Clinical Global Impressions scale (CGI) score, and social and occupational functioning. Results: Mean (SD) OASIS scores decreased from 10.8 (3.8) at baseline to 6.3 (4.5) at week 12, corresponding to a -42.6% reduction (P < .0001). Depressive symptoms (P < .0001), CGI-Severity scale scores (P = .0008), and functioning (P = .04) improved significantly. Adverse events were reported in 25 (80.6%) of 31 participants and included fatigue, low mood, and hot flushes or cold chills. There were no serious and/or unexpected adverse events. Conclusions: These findings suggest that CBD can reduce anxiety severity and has an adequate safety profile in young people with treatment-resistant anxiety disorders. Randomized controlled trials are needed to confirm the efficacy and longer-term safety of this compound. Trial Registration: New Zealand Clinical Trials Registry (ANZCTR) identifier: ACTRN12617000825358.