Cannabinoids for Anxiety & Tourette’s: Evidence from Systematic Reviews and Meta-Analyses in Cannabis Research
Clinical Takeaway
Systematic review and meta-analysis evidence suggests that cannabinoid formulations show measurable effects on anxiety-related disorders, though the quality and consistency of that evidence varies across specific conditions and formulations. Clinicians should interpret these findings carefully, as regulatory expansion has outpaced the rigorous trial data needed to make strong prescribing recommendations. Tourette syndrome was also examined alongside anxiety disorders, reflecting the overlapping neurobiological targets relevant to cannabinoid therapy.
#28 Effects of Different Cannabinoid Formulations on Anxiety-Related Disorders, and Tourette Syndrome: A Systematic Review and Meta-Analysis.
Citation: Raminelli Adrieli Oliveira et al.. Effects of Different Cannabinoid Formulations on Anxiety-Related Disorders, and Tourette Syndrome: A Systematic Review and Meta-Analysis.. Cannabis and cannabinoid research. 2025. PMID: 40956670.
Design: 6 Journal: 1 N: 0 Recency: 2 Pop: 2 Human: 1 Risk: -2
- Preclinical only
Abstract: Introduction: Cannabinoid formulations have been increasingly proposed as therapeutic potential options for anxiety disorders (ADs). Several countries have expanded regulatory frameworks facilitating access to these compounds due to their alleged therapeutic benefits, including their application in ADs. Given its public health significance, we evaluated existing evidence regarding the efficacy of different medical cannabinoids as interventions for ADs and related mental conditions. Methods: A comprehensive search was conducted in PubMed, Embase, PsycInfo, Web of Science, Scielo, and Lilacs databases. We included randomized controlled trials (RTCs) assessing the effects of various cannabinoid formulations on patients with ADs and related conditions. Distinct meta-analyses were performed for cannabinoid subtypes. Analyses were conducted using Jamovi software, relying on standardized mean difference (SMD) calculations of pre/post-intervention score changes for both intervention and control groups. Results: We incorporated 21 placebo-controlled RCTs, examining cannabinoid interventions in social anxiety disorder (SAD = 5), generalized anxiety disorder (GAD = 1), post-traumatic stress disorder (PTSD = 7), obsessive-compulsive disorder (OCD = 1), and Tourette syndrome (TS = 7). Data extraction indicated considerable heterogeneity across outcomes, including clinical symptoms, neuroimaging findings, well-being, psychosocial functioning, safety, and tolerability. In studies utilizing pure or enriched CBD, the meta-analytic measure indicated a nonsignificant difference (SMD = -0.40; 95% CI: -0.84/0.03). However, a subgroup analysis of pure CBD compounds yielded a moderate, statistically significant effect size (SMD: -0.61, 95% CI: -1.15/-0.07). For studies investigating pure or enriched delta-9-tetrahydrocannabinol (Δ9-THC), the meta-analytic measure was -0.65 (95% CI: -1.06/-0.24), suggesting a moderate, significant effect favoring Δ9-THC-dominant compounds. In meta-analyses
What This Study Teaches Us
Pure CBD showed a modest statistically significant benefit for anxiety in a subgroup analysis, but when CBD studies were pooled together (pure and enriched forms), the effect disappeared and was no better than placebo. The evidence remains mixed across different anxiety disorders and cannabinoid types.
Why This Matters Clinically
Clinicians are increasingly asked about cannabis for anxiety, and patients see marketing claims about CBD efficacy. This meta-analysis of 21 RCTs provides a reality check: the signal for pure CBD is weak and inconsistent, suggesting we should be cautious about positioning it as a proven first-line option for anxiety disorders.
Study Snapshot
| Study Design | Systematic review and meta-analysis of 21 placebo-controlled randomized controlled trials |
| Population | Adults with anxiety disorders (social anxiety disorder n=5 studies, generalized anxiety disorder n=1, PTSD n=7, OCD n=1) and Tourette syndrome (n=7 studies) |
| Intervention | Various cannabinoid formulations (pure CBD, enriched CBD, and other cannabinoid types); specific doses and durations not fully detailed in abstract |
| Primary Outcome | Standardized mean difference in anxiety symptom scores pre and post-intervention compared to placebo |
| Key Result | Pure or enriched CBD pooled: SMD = -0.40 (not significant); pure CBD alone: SMD = -0.61 (moderate effect, statistically significant but confidence interval barely excludes zero) |
Where This Paper Deserves Skepticism
The abstract is incomplete (cuts off mid-sentence), making full assessment difficult. The ‘significant’ pure CBD result is driven by a modest effect size with a confidence interval that just excludes zero, suggesting marginal clinical meaningfulness. With only 21 RCTs spread across five different conditions and heterogeneous outcomes, the power to detect true effects is limited. The considerable heterogeneity acknowledged by authors suggests real differences between studies that a simple pooled estimate may mask, and we don’t know from the abstract whether publication bias or funding sources were assessed.
Dr. Caplan’s Take
I’ve watched CBD marketing outpace the evidence for years, and this meta-analysis confirms my clinical impression. When you actually pool the data carefully, pure CBD shows a borderline signal that disappears when you include enriched formulations. The confidence intervals are tight enough that we’re not looking at a robust effect hiding in noise. For my patients with anxiety, I’m not seeing evidence robust enough to recommend CBD as a first-line option, though I acknowledge some individuals report benefit. Until we have larger, longer trials with consistent outcome measures, I counsel patients that the science is still early.
Clinical Bottom Line
For anxiety disorders, cannabinoid formulations (especially CBD) do not show convincing efficacy over placebo in this meta-analysis. Clinicians should remain cautious about marketing claims and set realistic expectations with patients seeking CBD for anxiety.
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