A recent study has cast doubt on the efficacy of medical cannabis, revealing that its risks may outweigh its benefits. The research, led by Dr. Michael Hsu, an addiction psychiatrist at UCLA, found “insufficient evidence” to support most claims regarding the advantages of medical marijuana. This study emerges as more Americans rely on cannabis for conditions such as chronic pain, anxiety, and sleep disorders. Medical cannabis is now legal in 40 states and Washington, D.C., with nearly 90% of adults supporting its use when prescribed by a physician.
Dr. Hsu and his team conducted a comprehensive review of over 2,500 scientific papers published from January 2010 to September 2025. They compared medical cannabis available at dispensaries with FDA-approved pharmaceutical-grade cannabinoids, including THC, a psychoactive compound, and CBD, which does not induce a high. The findings indicated that while FDA-approved medications may effectively alleviate nausea from chemotherapy, stimulate appetite in patients with HIV/AIDS, and reduce severe pediatric seizure disorders, the benefits of medical cannabis were not as robust as public perception suggests.
In their analysis, the researchers noted that more than half of cannabis users seek relief for acute pain; however, there is no solid clinical evidence supporting its effectiveness for this purpose. Current medical guidelines do not recommend cannabis-based treatments as a first-line option for managing pain. The study also highlighted weak or inconclusive evidence regarding the effectiveness of medical cannabis for conditions such as insomnia, anxiety, PTSD, Parkinson’s disease, and rheumatoid arthritis.
In terms of potential risks, the study raised significant concerns. Long-term usage of high-potency cannabis among adolescents correlates with increased rates of psychotic symptoms, with 12.4% of high-potency users affected compared to 7.1% of those using low-potency products. Additionally, 19.1% of adolescents who used high-potency cannabis developed generalized anxiety disorder, in contrast to 11.6% of their peers using lower potency.
The findings also revealed that approximately 29% of medical cannabis users may meet the criteria for cannabis use disorder, a condition characterized by a compulsive urge to use cannabis, increased tolerance, and withdrawal symptoms upon cessation. This risk is particularly pronounced for individuals who begin using cannabis before the age of 18, as they are four to seven times more likely to develop dependence compared to adults.
Moreover, daily use of medical cannabis, especially high-potency or inhaled products, may elevate the risk of cardiovascular problems. Research indicates a higher likelihood of heart attacks, strokes, and coronary artery disease among daily users compared to those who use cannabis occasionally. In response to these findings, Dr. Hsu and his colleagues recommended that healthcare providers screen patients for cardiovascular disease and psychotic disorders before prescribing THC-containing products. They emphasized the importance of weighing potential harms against benefits when considering medical cannabis for patients.
“Clear guidance from clinicians is essential to support safe, evidence-based decision-making when discussing medical cannabis with their patients,” stated Dr. Hsu.
The researchers acknowledged limitations in their study, noting that it was not a systematic review and did not include a formal risk-of-bias assessment. They also indicated that some included research was observational and possibly influenced by confounding factors. Due to variations in study design, cannabis products tested, and participant characteristics, the findings may not universally apply to all patients.
“Further research is crucial to better understand the potential benefits and risks of medical cannabis,” Dr. Hsu added. “By supporting more rigorous studies, we can provide clearer guidance and improve clinical care for patients.”
The timing of these findings coincides with speculation regarding potential changes in cannabis classification at the federal level in the United States. Currently categorized as a Schedule I drug, cannabis is alongside substances like heroin and LSD. Reports suggest that President Trump may move to reclassify cannabis to Schedule III, recognizing it as less dangerous and more acceptable for medical use. Following these discussions, cannabis stocks surged, reflecting market optimism about potential regulatory changes.
