Researchers say there is scant proof that cannabis helps with the three leading afflictions for which people claim to use it: insomnia, pain and anxiety, with the most recent study reinforcing this conclusion.
Although millions of Americans use cannabis for medical reasons, the scientists said their findings suggest there is not enough evidence to support much of that medicinal use, reports WBUR – Boston’s NPR.
The research, published in the Journal of the American Medical Association, reviewed the scientific evidence behind claims of medical benefits for cannabis and cannabinoids, the active compounds in cannabis.
Dr Kevin Hill, director of the Division of Addiction Psychiatry at Beth Israel Deaconess Medical Centre, is among the researchers who reviewed the evidence, which he said is the “most thorough and up to date review” yet.
He said while the review found there are some ailments, like nausea from cancer treatment, for which cannabis and cannabinoids are helpful, the evidence is scant to support its growing use for a variety of issues. Hill also said there are risks to cannabis use, such as cardiovascular complications and addiction, so patients and doctors should consider alternatives.
“What we’re hopeful for is that our review will encourage sensible, evidence-based conversations between clinicians and patients and hopefully steer them towards evidence-based treatments,” he added.
Research has been hampered because cannabis is classified federally as an illegal drug. But more than half of states and the District of Columbia have legalised its use, creating a US cannabis industry that’s worth tens of billions of dollars.
Hill believes cannabis businesses, and states getting tax revenues from them, should fund more scientific research.
“A big part of the problem here is that there’s a lot of money involved here, a lot of people and states like Massachusetts are frankly making a lot of money on cannabis,” he observed.
The study found that 27% of adults in the US and Canada have, at one point, used cannabis for medical reasons. More than 10% of the American population reported using cannabidiol (CBD), a cannabis extract without psychoactive properties, for therapeutic purposes.
The research did point out that there are medical benefits for the FDA-approved cannabis for cancer patients’ nausea, appetite stimulation and some seizures.
“I’m not saying there are not clinical uses for cannabis or cannabinoids,” Hill said. “But we have to acknowledge that at this point there’s overwhelmingly negative evidence and the risks in most cases outweigh the benefits.”
Study details
Therapeutic Use of Cannabis and Cannabinoids: A Review
Michael Hsu, Arya Shah, Kevin Hill, et al.
Published in JAMA Network on 26 November 2025
Abstract
Importance
Approximately 27% of adults in the US and Canada report having ever used cannabis for medical purposes. An estimated 10.5% of the US population reports using cannabidiol (CBD), a chemical compound extracted from cannabis that does not have psychoactive effects, for therapeutic purposes.
Observations
Conditions for which cannabinoids have approval from the US Food and Drug Administration include HIV/AIDS–related anorexia, chemotherapy-induced nausea and vomiting, and certain paediatric seizure disorders. A meta-analysis of randomized clinical trials reported a small but significant reduction in nausea and vomiting from various causes (eg, chemotherapy, cancer) when comparing prescribed cannabinoids (eg, dronabinol, nabilone) with placebo or active comparators (eg, alizapride, chlorpromazine; standardized mean difference [SMD], −0.29 [95% CI, −0.39 to −0.18]). A meta-analysis of randomised clinical trials among patients with HIV/AIDS reported that cannabinoids had a moderate effect on increasing body weight compared with placebo (SMD, 0.57 [95% CI, 0.22 to 0.92]). Evidence-based guidelines do not recommend the use of inhaled or high-potency cannabis (≥10% or 10 mg Δ9-tetrahydrocannabinol [Δ9-THC]) for medical purposes. High-potency cannabis compared with low-potency cannabis use is associated with increased risk of psychotic symptoms (12.4% vs 7.1%) and generalised anxiety disorder (19.1% vs 11.6%). A meta-analysis of observational studies reported that 29% of individuals who used cannabis for medical purposes met criteria for cannabis use disorder. Daily inhaled cannabis use compared with nondaily use was associated with an increased risk of coronary heart disease (2.0% vs 0.9%), myocardial infarction (1.7% vs 1.3%), and stroke (2.6% vs 1.0%). Evidence from randomised clinical trials does not support the use of cannabis or cannabinoids for most conditions for which it is promoted, such as acute pain and insomnia. Before considering cannabis or cannabinoids for medical use, clinicians should consult applicable institutional, state, and national regulations; evaluate for drug-drug interactions; and assess for contraindications (eg, pregnancy) or conditions in which risks likely outweigh benefits (eg, schizophrenia or ischemic heart disease). For patients using cannabis or cannabinoids for treatment of medical conditions, clinicians should discuss harm reduction strategies, including avoiding concurrent use with alcohol or other central nervous system depressants such as benzodiazepines, using the lowest effective dose, and avoiding use when driving or operating machinery.
Conclusions and Relevance
Evidence is insufficient for the use of cannabis or cannabinoids for most medical indications. Clear guidance from clinicians is essential to support safe, evidence-based decision-making. Clinicians should weigh benefits against risks when engaging patients in informed discussions about cannabis or cannabinoid use.
JAMA Network article – Therapeutic Use of Cannabis and Cannabinoids: A Review (Open access)
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