New Study Questions the Real Medical Benefits of Marijuana

A major new scientific review has raised fresh questions about the true health benefits of medical marijuana, suggesting that its effectiveness for many conditions may have been overstated. The study, recently published in the prestigious medical journal JAMA (Journal of the American Medical Association), challenges widely held assumptions about cannabis as a reliable medical treatment.

Marijuana is one of the most commonly used psychoactive substances worldwide, and in recent years, many U.S. states have significantly relaxed laws governing both medical and recreational cannabis use. Medical marijuana is frequently prescribed to manage chronic pain, particularly when conventional treatments fail or when physicians seek alternatives to highly addictive opioid medications. It is also sometimes used to help patients undergoing chemotherapy, primarily to reduce nausea and vomiting.

Scope and Findings of the JAMA Review

The JAMA study analyzed data from more than 2,500 clinical trials conducted between January 2010 and September 2025, examining the medical use of cannabis and cannabinoid-based drugs. These substances include compounds approved by the U.S. Food and Drug Administration (FDA) for specific conditions, such as HIV/AIDS-related anorexia, chemotherapy-induced nausea and vomiting, and certain rare pediatric seizure disorders.

While the review did identify limited evidence of benefit in some cases, the researchers concluded that cannabis is far less effective for most medical conditions than public perception suggests. In particular, evidence supporting its widespread use for chronic pain, anxiety, or general wellness was found to be inconsistent or weak.

Dr. Michael Hsu, the study’s lead author and an addiction psychiatrist at the University of California, Los Angeles (UCLA), emphasized the disconnect between expectations and evidence. He noted that many patients seek cannabis believing it to be a proven treatment, despite the lack of strong scientific support for many claims. According to Dr. Hsu, clear, evidence-based guidance from healthcare providers is critical to ensure patients make informed decisions.

“Patients deserve honest conversations about what the science does and doesn’t tell us about medical cannabis,” he said.

Health Risks and Safety Concerns

Beyond questions of effectiveness, the study also highlighted significant health risks associated with both medical and recreational cannabis use. One key finding was that approximately 29% of people who use cannabis medically meet the criteria for cannabis use disorder, a condition characterized by dependency and impaired control over use.

The review also found associations between daily cannabis use and increased cardiovascular risks, including a higher likelihood of heart attacks and strokes, compared with non-users. These findings align with growing concerns among cardiologists and public health experts about the long-term effects of frequent cannabis consumption.

Despite these concerns, the study did confirm a small but statistically significant reduction in nausea and vomiting among patients receiving chemotherapy, supporting its limited use in specific clinical contexts.

Ongoing Debate and Need for Further Research

Dr. Hsu and his colleagues stressed that more rigorous, high-quality research is essential to fully understand both the benefits and risks of medical cannabis. Improved study designs and standardized dosing could help clarify where cannabis may have legitimate medical value and where it does not.

Speaking to The New York Times, Dr. Kevin Hill, a co-author of the study and an addiction psychiatrist at Beth Israel Deaconess Medical Center in Boston, acknowledged that cannabis does have valid medical applications. However, he cautioned that some individuals may label their use as “medical” when it is, in reality, recreational.

“There are some legitimate purposes for these compounds,” Dr. Hill said. “And there’s a whole other group of people who are saying they’re using it medically, but they’re really not.”

Conclusion

Overall, the JAMA review suggests that while medical marijuana can offer modest benefits in select cases, it is not a cure-all and carries meaningful risks that are often overlooked. As legalization expands and use becomes more widespread, experts emphasize the importance of evidence-based medicine, transparent patient education, and continued scientific investigation to guide responsible use.

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Sources

• JAMA (Journal of the American Medical Association). Cannabis and Cannabinoids for Medical Use: A Systematic Review

• U.S. Food and Drug Administration (FDA). FDA-Approved Cannabinoid Medications

• University of California, Los Angeles (UCLA) – Department of Psychiatry

• New York Times. What the Science Really Says About Medical Marijuana

• National Institute on Drug Abuse (NIDA). Cannabis (Marijuana) DrugFacts

• American Heart Association. Cannabis Use and Cardiovascular Health