Overview
- A Lancet Psychiatry systematic review pooled 54 randomized trials from 1980 to 2025 covering 2,477 participants.
- Researchers found no efficacy for depression, anxiety or PTSD and only limited, low-quality signals for outcomes such as sleep, tics and easing cannabis withdrawal.
- Harms were documented, including more adverse events overall and increased cocaine cravings in people with cocaine-use disorder.
- Most trials used oral formulations like capsules, sprays or oils, leaving even weaker evidence for smoked products commonly used in practice.
- A recent JAMA analysis reached similar conclusions, and experts cite widespread approvals and rising use in the US, Canada and Australia alongside potency-linked risks of addiction and psychotic disorders.