Cannabinoids for the treatment of mental disorders and symptoms of mental disorders: a systematic review and…
This review found THC did not help any mental-health outcome but doubled the odds of side effects — if I am using cannabis for my mood, what are we actually trading away?
Top of the evidence hierarchy, independently funded. how we score evidence
Botanical cannabis has never been FDA-approved for any psychiatric indication. Its federal scheduling changed partially in 2026 and is still unsettled: a DEA/DOJ final rule effective 28 April 2026 (Federal Register document 2026-08176) moved two narrow categories — marijuana contained in an FDA-approved drug product, and marijuana subject to a state medical marijuana license — from Schedule I to Schedule III, and 21 CFR 1308.13(g) now lists them there. Everything else, including adult-use and recreational cannabis, remains in Schedule I under 21 CFR 1308.11(d), alongside naturally occurring tetrahydrocannabinols. A separate proposal to reschedule marijuana broadly to Schedule III is still pending: DEA published a notice of hearing on 28 April 2026 setting proceedings to begin 29 June 2026, and as of 18 August 2026 no final rule broadly rescheduling marijuana had been published. Meanwhile most US states run medical and/or adult-use programmes whose products are regulated by state, not federal, standards. Some pharmaceutical cannabinoids (for example dronabinol) are separately FDA-approved for non-psychiatric uses such as chemotherapy-induced nausea and AIDS-related anorexia.
Pooling 40 randomised trials (n=3,067) across depression, anxiety, ADHD, Tourette syndrome, PTSD, and psychosis, pharmaceutical THC produced only a very-low-certainty small improvement in anxiety among people whose primary problem was another medical condition (SMD -0.25), worsened negative symptoms of psychosis in the single trial that measured it (SMD 0.36), and did not significantly affect any other primary outcome. It roughly doubled the odds of adverse events (OR 1.99) and nearly tripled withdrawals due to adverse events (OR 2.78).
Worth asking
This review found THC did not help any mental-health outcome but doubled the odds of side effects — if I am using cannabis for my mood, what are we actually trading away?
Source
Cannabinoids for the treatment of mental disorders and symptoms of mental disorders: a systematic review and meta-analysis. — Black N, Stockings E, Campbell G, et al. (2019)
Top-tier peer-reviewed journal
Read the source: https://doi.org/10.1016/S2215-0366(19)30401-8
DOI: 10.1016/S2215-0366(19)30401-8
How this was scored
- Study design
- Meta-analysis of randomised trials
- Funding
- Independently funded
- Published in
- Top-tier peer-reviewed journal
- Sample size
- 3,067
- Preregistered
- Yes
- Conflicts disclosed
- Yes
- Independent of proponent
- Yes
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published August 19, 2026.
Questions
How strong is the evidence behind this?
Resolv rates this source "gold standard". Top of the evidence hierarchy, independently funded. It scores 98 out of 100 on our published rubric. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Cannabinoids for the treatment of mental disorders and symptoms of mental disorders: a systematic review and meta-analysis. — Black N, Stockings E, Campbell G, et al. (2019). Published in: Top-tier peer-reviewed journal. DOI: 10.1016/S2215-0366(19)30401-8. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Meta-analysis of randomised trials. Funding: Independently funded. The researchers were independent of whoever benefits from the result. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is cannabis-thc, marijuana, weed, thc, delta-9-tetrahydrocannabinol, medical cannabis, dronabinol, nabiximols FDA approved for this use?
No. Its current status is: Not FDA-evaluated for this use. Botanical cannabis has never been FDA-approved for any psychiatric indication. Its federal scheduling changed partially in 2026 and is still unsettled: a DEA/DOJ final rule effective 28 April 2026 (Federal Register document 2026-08176) moved two narrow categories — marijuana contained in an FDA-approved drug product, and marijuana subject to a state medical marijuana license — from Schedule I to Schedule III, and 21 CFR 1308.13(g) now lists them there. Everything else, including adult-use and recreational cannabis, remains in Schedule I under 21 CFR 1308.11(d), alongside naturally occurring tetrahydrocannabinols. A separate proposal to reschedule marijuana broadly to Schedule III is still pending: DEA published a notice of hearing on 28 April 2026 setting proceedings to begin 29 June 2026, and as of 18 August 2026 no final rule broadly rescheduling marijuana had been published. Meanwhile most US states run medical and/or adult-use programmes whose products are regulated by state, not federal, standards. Some pharmaceutical cannabinoids (for example dronabinol) are separately FDA-approved for non-psychiatric uses such as chemotherapy-induced nausea and AIDS-related anorexia.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.