Abstract
Background: Cannabidiol (CBD) is increasingly used as self-treatment for psychiatric symptoms despite limited evidence of efficacy. This systematic review examined clinical trials investigating effects of CBD on anxiety, mood, and trauma-related disorders and symptoms. Methods: Following PRISMA 2020 guidelines, MEDLINE, PsycINFO, and Embase were searched from inception to August 2026 for randomized controlled trials (RCTs) of CBD in adults with anxiety, mood, or trauma-related disorders or subthreshold anxiety, mood, or trauma-related symptoms. Risk of bias (RoB) was assessed using Cochrane RoB 2. Results: Of 733 publications identified, 12 reports from 10 RCTs met inclusion criteria: six examined anxiety, two mood / depressive, and four PTSD/trauma-related disorders or symptoms. In anxiety studies, CBD monotherapy reduced anxiety symptoms and negative self-evaluation in some populations, although effects varied across outcomes and dosing paradigms. Adjunctive CBD with exposure therapy for social anxiety disorder and panic disorder with agoraphobia provided no benefit over placebo. Trials in bipolar depression and depressive symptoms showed no CBD-specific effects. In trauma studies, CBD generally did not improve trauma-related, depressive, or anxiety symptoms. However, two reports from a single trial found that a single dose of CBD attenuated cognitive impairment induced by trauma-recall. One of these reports reported reduced anxiety among participants with nonsexual trauma. Two reports were low risk of bias, seven had some concerns, and three were high risk. Limitations: CBD adherence was objectively verified in three trials. The small, heterogeneous evidence base limited comparisons across diagnoses and outcomes. Conclusions: Evidence for CBD as treatment of anxiety, depressive, and trauma-related symptoms remains preliminary. Some anxiety trials found reductions in anxiety symptoms with CBD monotherapy, but findings were inconsistent across populations, outcomes, and dosing paradigms. Evidence was insufficient to determine CBD-specific effects on depressive or trauma-related symptoms. Future RCTs should standardize and objectively verify dosing and incorporate cognitive, physiological, and neurobiological outcomes.