Scientific advancement in cannabis challenges traditional clinical medicine criteria

The volume of scientific research on cannabis is growing rapidly worldwide. For the fifth consecutive year, researchers have published over 4,000 articles on the plant, according to data from the United States National Library of Medicine (PubMed). However, a recent review from the Journal of the American Medical Association (JAMA) points out that, under the criteria of traditional clinical medicine, the evidence of efficacy remains "weak or inconclusive" — an assessment that is relativized by doctors and researchers interviewed for the report.

According to Dr. Matheus Dzieva, this reading "does not reflect the totality of the available evidence, especially in conditions like chronic pain", an area where studies and clinical practice indicate consistent results.

Since 2015, there have been over 37,000 publications registered on the subject, according to an analysis by the organization NORML. The contrast between this academic volume and the conclusions of the JAMA review highlights a mismatch between the speed of basic scientific production and the rigidity of the classic pharmaceutical protocols adopted in clinical medicine.

Explosion of data in cannabis research

PubMed numbers indicate an unprecedented acceleration in academic interest in the subject. Over 70% of all historical scientific literature on the plant was produced in just the last decade.

By extending the analysis period to 2002, this rate rises to 90%. Paul Armentano, deputy director of the National Organization for the Reform of Marijuana Laws (NORML), comments on the density of this material in cannabis research.

Currently, the database records over 53,000 cited articles. They cover everything from biological mechanisms of action to safety and therapeutic efficacy, with over 450 specific studies dedicated to evaluating these aspects.

The "Gold Standard" counterpoint

In contrast to the quantitative volume, the JAMA review analyzed 15 years of data and over 2,500 trials. The analysis adopted pharmacological "gold standard" criteria, focusing on randomized and double-blind clinical trials.

The study's authors point out a discrepancy between the popular use of the substance and the robustness of clinical evidence. Often focused on chronic pain and anxiety, cannabis research still shows insufficient evidence for acute pain relief under this methodological perspective.

Dr. Matheus Dzieva agrees with caution regarding acute pain but defends the strength of evidence for other conditions, challenging the generalization of negative results.

"In acute pain, yes, specific studies are lacking, JAMA is right about that. But when we look at chronic pain, especially neuropathic pain, the evidence is robust," says Dzieva. "A 2023 meta-analysis shows that cannabis works, significantly reducing pain. And thousands of doctors prescribe it because they see real results."

In addition to efficacy, the review raised safety concerns. It is estimated that about 30% of medicinal users may meet criteria for substance use disorder.

The text recommends caution, specifically regarding inhalation. It also warns about the consumption of products not regulated by the Food and Drug Administration (FDA).

However, the methodology used to analyze this volume is subject to criticism. Francisney Nascimento, coordinator of the Medicinal Cannabis and Psychedelic Science Laboratory at the Federal University of Latin American Integration (UNILA), warns of the error of generalization in systematic reviews treating the plant as a single drug.

Historical and educational gap in cannabis research

The divergence between the JAMA conclusions and the PubMed numbers reflects a complex historical context. Prohibitionism has hindered standardized clinical trials for decades.

Francisney Nascimento points out that, in addition to history, there is an economic barrier to conducting the large clinical trials required by high-impact reviews. "Since these molecules cannot be patented, the industry does not invest much, and then there is a lack of studies to change this basis," Nascimento analyzes, citing the efforts of his laboratory in Foz do Iguaçu to conduct independent trials.

While basic science advances, the final end of the chain — the prescribing physician — often feels unsupported. The JAMA review itself notes that 86% of surveyed doctors stated they need more education on the subject.

For Dr. Matheus Dzieva, the educational problem is as serious as the complexity of the research. "Cannabis is not included in any medical school curriculum in Brazil while the scientific literature grows exponentially," laments the doctor, emphasizing that there are still open questions about drug interactions and at-risk groups that generate legitimate insecurity.

"It's not just one problem, it's two: lack of access in education and questions that are still being answered."