When Science Gets It Wrong: The Importance of Research Integrity in Psychedelic Studies
In February 2024, a scientific paper made headlines with a bold claim: among all the psychedelics being studied for mental health treatment, only DMT (dimethyltryptamine) showed a "statistically significant association with an increase in peripheral BDNF levels" in humans [1]. BDNF, or brain-derived neurotrophic factor, is a protein that plays a crucial role in brain health and neuroplasticity. For people considering psychedelic therapy, this seemed like important information that might influence treatment decisions.
But by May 2025, that same paper had been retracted from the Journal of Psychopharmacology after the authors themselves requested to make "significant changes" to their statistical analysis, meta-analysis, discussion, and figures [1]. The retraction notice revealed that an independent researcher had spotted inconsistencies in the work, and when the authors tried to correct their analysis, they found problems so substantial that the entire paper had to be withdrawn. This story isn't just about one flawed study. It's about why research integrity matters so much in the rapidly evolving field of psychedelic medicine, and what people considering these treatments need to know about evaluating the science behind them. As psychedelic therapies move closer to mainstream medical practice, understanding how to distinguish reliable research from questionable claims becomes increasingly important for patients, families, and healthcare providers.
The Retracted Study: What Went Wrong
The retracted paper was a meta-analysis, which means it combined data from multiple smaller studies to try to draw broader conclusions about psychedelics and BDNF levels. Meta-analyses are considered a high level of evidence in medical research because they can identify patterns across multiple studies that might not be apparent in any single study alone. When done correctly, they provide valuable insights that can guide clinical practice and future research.
The original study analyzed nine different papers examining the effects of various psychedelics on BDNF levels in people. The authors concluded that among all the substances studied – including psilocybin, LSD, and MDMA – only DMT showed a statistically significant increase in BDNF levels [1]. This finding was potentially important because BDNF is thought to play a role in the therapeutic effects of psychedelics, and it might have suggested that DMT had unique advantages over other psychedelic medicines. However, the story began to unravel when Dr. Gregor Hasler, a professor of psychiatry at the University of Fribourg, was working on his own similar analysis of psychoplastogens – substances that promote neuroplasticity, including DMT and other psychedelics. Dr. Hasler's analysis found no evidence that these substances increase BDNF levels in people, which was in "very deep disagreement" with the published paper [1].
Dr. Hasler contacted the authors of the original study to discuss the discrepancies. Rather than dismissing his concerns, the authors acknowledged that there were problems with their work. As Dr. Hasler told The Transmitter, "they were really nice, and they agreed that there were mistakes" [1]. This response, while professionally appropriate, revealed that the original analysis had significant flaws. When the authors attempted to correct their work, they discovered that the problems were more extensive than initially apparent. According to the retraction notice, they requested changes to virtually every aspect of their paper: the "statistical analysis, meta-analysis, discussion, figures and supplementary material," plus the removal of two figures and the addition of four others [1]. They also requested changes to the authorship of the paper.
The journal determined that these requested changes were so substantial that they "calls into question the reliability of the original research and the conclusions" [1]. Rather than allowing the authors to publish what would essentially be an entirely different paper, the journal made the decision to retract the original work entirely. This case illustrates several important points about how science is supposed to work. First, it shows the value of having multiple researchers working on similar questions. If Dr. Hasler hadn't been conducting his own analysis, the errors in the original paper might have gone undetected for much longer. Second, it demonstrates the importance of researchers being willing to acknowledge and address problems with their work when they're identified. Finally, it shows how the peer review and publication system, while not perfect, has mechanisms for correcting the scientific record when errors are discovered.
Why Research Integrity Matters for Patients
For people considering psychedelic therapy, research integrity isn't just an abstract academic concern – it has real implications for treatment decisions and patient safety. When flawed research makes it into the scientific literature, it can influence how doctors prescribe treatments, how patients choose between options, and how resources are allocated for future research.
In the case of the retracted DMT study, the original conclusions might have led some people to believe that DMT was superior to other psychedelics for promoting brain health. This could have influenced treatment decisions, with patients potentially seeking out DMT-based therapies over other options that might have been more appropriate for their specific conditions. While DMT-based therapies are not yet widely available for most mental health conditions, the research findings could have influenced the direction of future clinical trials and drug development efforts.
The stakes become even higher when we consider that psychedelic therapies are still experimental for most conditions. Unlike established treatments where we have decades of safety and efficacy data, psychedelic medicines are still being studied to understand their optimal uses, dosing, and potential risks. In this context, accurate research is crucial for ensuring that these promising treatments are developed safely and effectively. The stakes become even higher when we consider that psychedelic therapies are still experimental for most conditions. Unlike established treatments where we have decades of safety and efficacy data, psychedelic medicines are still being studied to understand their optimal uses, dosing, and potential risks. In this context, accurate research is crucial for ensuring that these promising treatments are developed safely and effectively.
Patient safety is perhaps the most important consideration. While the retracted study didn't directly put anyone at risk, research errors in other contexts could potentially lead to inappropriate treatment recommendations, inadequate safety monitoring, or missed opportunities to identify important side effects or drug interactions.
How to Evaluate Psychedelic Research as a Patient
Given the importance of research quality, how can people considering psychedelic therapy evaluate the scientific evidence for themselves? While most patients aren't expected to become research experts, there are several key factors that can help distinguish reliable studies from questionable ones. First, consider the source of the research. Studies published in well-established, peer-reviewed journals have typically undergone more rigorous review than those published in newer or less prestigious publications. Journals like the New England Journal of Medicine, JAMA Psychiatry, Nature Medicine, and the Journal of Psychopharmacology have established reputations for maintaining high standards. However, even prestigious journals can occasionally publish flawed research, as the retracted DMT study demonstrates.
Look for studies that have been replicated by independent research groups. Single studies, no matter how well-designed, can sometimes produce misleading results due to chance, measurement errors, or other factors. When multiple independent research teams reach similar conclusions using different methods and populations, the findings are much more likely to be reliable.
Pay attention to study design and size. Randomized controlled trials, where participants are randomly assigned to receive either the treatment or a placebo, are generally considered the gold standard for testing medical treatments. Larger studies are typically more reliable than smaller ones, though even small studies can provide valuable information if they're well-designed.
Be cautious of research that makes dramatic claims or suggests that one treatment is dramatically superior to all others. Medical breakthroughs do happen, but they're relatively rare. Most advances in medicine are incremental, building on previous research rather than completely overturning established knowledge.
Consider who funded the research and whether the researchers have financial conflicts of interest. While industry funding doesn't automatically make research unreliable, it's important to know when researchers have financial stakes in the outcomes of their studies. The best research is often funded by government agencies or independent foundations that don't have commercial interests in the results.
Look for transparency in how the research was conducted. Good studies provide detailed information about their methods, include appropriate statistical analyses, and acknowledge limitations in their findings. Be wary of research that makes broad claims based on limited data or that doesn't acknowledge potential weaknesses in the study design.
The Current State of Psychedelic Research
Despite the setback represented by the retracted DMT study, the overall state of psychedelic research remains promising. Multiple high-quality studies have demonstrated the potential benefits of psilocybin-assisted therapy for depression, anxiety, and other mental health conditions [2][3]. MDMA-assisted therapy has shown promise for post-traumatic stress disorder, and research into other psychedelics continues to advance.
The key is to maintain appropriate scientific rigor while continuing to explore these promising treatments. As Dr. Hasler noted about the retraction, "the good thing here is that they realized that they did [make] mistakes, and they contacted the journal. So the system works, so you can say it's also part of an extended peer review" [1].
The Importance of Critical Thinking
The retraction of the DMT study serves as an important reminder that science is a self-correcting process, but only when researchers, reviewers, and the broader scientific community maintain high standards and remain vigilant for errors. For people considering psychedelic therapy, this case underscores the importance of working with healthcare providers who stay current with the latest research and who can help interpret scientific findings in the context of individual treatment decisions.
Rather than being discouraged by this example of flawed research, patients and providers should see it as evidence that the scientific system has mechanisms for identifying and correcting errors. The fact that the problems with this study were identified and addressed demonstrates the importance of ongoing scrutiny and the value of having multiple researchers working on similar questions. As psychedelic medicine continues to evolve, maintaining this commitment to research integrity will be essential for ensuring that these promising treatments reach the people who can benefit from them safely and effectively.
References
[1] Hill, M. (2025, June 11). Psychedelics meta-analysis retracted after authors request 'significant changes'. The Transmitter: Neuroscience News and Perspectives. https://doi.org/10.53053/EJDW1182
[2] Schipper, S., Nigam, K., Schmid, Y., Piechotta, V., Ljuslin, M., Beaussant, Y., Schwarzer, G., & Boehlke, C. (2024). Psychedelic-assisted therapy for treating anxiety, depression, and existential distress in people with life-threatening diseases. Cochrane Database of Systematic Reviews, 9(9), CD015383. https://pubmed.ncbi.nlm.nih.gov/39260823/
[3] Li, L.-J., Shi, Z.-M., Huang, X.-B., Ning, Y.-P., Wu, H.-W., Yang, X.-H., & Zheng, W. (2024). Psilocybin for major depressive disorder: a systematic review of randomized controlled studies. Frontiers in Psychiatry, 15, 1416420. https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2024.1416420/full