The Johns Hopkins Center for Psychedelic and Consciousness Research hosted the Hopkins-Oxford Psychedelics Ethics (HOPE) Summit in August 2024 in Washington, D.C. Participants revisited the June 2023 statement from the Oxford Summit, expanded stakeholder input, considered implementation guidelines, and fostered new and ongoing collaborations. Last but not least, participants aimed to get a sense for the major issues and directions in the field to help guide the organizer’s drafting of a response to the recent Congressional Request for Information on the implementation of potential psychedelic therapies, led by Berman Institute of Bioethics doctoral student and HOPE fellow Katherine Cheung. The primary topics of both the Oxford and Johns Hopkins meetings are summarized in the HOPE statement.

David Yaden, the Griffiths Professor of Psychedelic Research, answers a potpourri of questions about psychedelics research.

Please tell us about the purpose of the Psychedelic Risks, Side Effects, and Potential Harms video.
DBY: We aim to uphold the tripartite mission of the Johns Hopkins University School of Medicine, so we engage in frequent public education about psychedelics. There is a lot of extreme messaging out there that is not evidence-based: Some think psychedelics are going to somehow cure every mental disorder, while others still think psychedelics are merely drugs of abuse with no redeeming value. Neither of these perspectives fits the facts. This public service announcement was a way to offer some information to the general public in a short and simple video that provides an evidence-based perspective. We have observed substantial potential for psychedelics as therapeutics when administered under supportive conditions, and there are other benefits to psychedelics that we are still quantifying, but there are also real risks — and it is part of our work to make sure these are communicated. (Suggested reading: Yaden, D. B., Potash, J. B., & Griffiths, R. R. (2022). “Preparing for the bursting of the psychedelic hype bubble.” JAMA Psychiatry, 79(10), 943-944)

Could you expand on the current informed-consent process in psychedelics research and what kind of research would help improve the process?
DBY: Psychedelics do not pose unique challenges to informed consent, as there are plenty of other medical interventions that involve potentially major changes to function and identity — so psychedelics are not exceptional in this regard. But psychedelics do have a set of features that makes them distinct and are, therefore, worth substantial consideration.

Compared to many interventions, classic psychedelics (like psilocybin) have a quite good safety profile, at least insofar as it is very difficult to die from an overdose or become addicted. However, the informed-consent process in psychedelic research is complex because, among other reasons, psychedelic substances can involve shifts in perception that are very difficult to describe. Traditional consent models often struggle to convey how psychedelic experiences feel, or fully address mid-session capacity changes. Research needs include (1) comparative studies on different consent-delivery methods (including enhanced consent methods like video modules or peer education); (2) adaptive consent processes that ensure participants remain informed and safe throughout preparation, the session itself, and follow-up and (3) participant feedback on potential improvements to consent documents. We are partnering with the Johns Hopkins Berman Institute of Bioethics to improve our study consent documents. (Suggested reading: Cheung, K., Earp, B. D., Patch, K., & Yaden, D. B. (2025). “Distinctive but not exceptional: The risks of psychedelic ethical exceptionalism.” The American Journal of Bioethics, 25(1), 16-28)

In your adverse events (AE) meta-analysis, what were your findings of serious adverse events (SAEs) and non-serious adverse events (NSAEs) in clinical settings?
DBY: This is a project led by current Hopkins psychiatry resident Jared Hinkle. It is worth emphasizing that these results derive from studies on classic psychedelics (like psilocybin) in carefully controlled clinical settings, and further, to recognize that these studies have closely screened participants to exclude those at increased risk for cardiovascular or psychiatric complications (particularly psychosis). So these conclusions should not be generalized to other settings, such as recreational use.

For an adverse event to be classified as serious, it must involve potentially life-threatening consequences, hospitalization or death. Among studies of “healthy” participants without known psychiatric conditions, we identified no reports of SAEs during or after treatment with the classic psychedelics: psilocybin, LSD, DMT, or 5-MeO-DMT. The SAE rate was approximately 4% in studies with participants who had psychiatric conditions such as depression, anxiety or substance use disorders, but in most cases, it was difficult to assess the potential causal relationship between the SAE and psychedelic experience. We are not entirely sure why the SAE rate was higher for participants with psychiatric conditions. It could be due to higher baseline risk for dangerous occurrences in these populations, more intensive surveillance for adverse events in the relevant trials, exacerbation of psychiatric disorders by psychedelic substances in predisposed individuals or other reasons entirely. We advocate for improved and more standardized adverse event recording and reporting practices in this field.

We separately analyzed NSAEs that were significant enough to warrant medical or psychiatric evaluation. Rates of NSAEs involving suicidal behavior, psychotic symptoms, manic symptoms, cardiovascular events and hallucinogen-persisting perception disorder (HPPD) were about 1% or less across each classic psychedelic and each category of participant, with one exception being that about 3% of participants given DMT experienced some cardiovascular adverse event that required medical intervention. “Other” NSAEs that didn’t fit one of these categories occurred in less than 2% of healthy participants and less than 4% of participants with neuropsychiatric conditions, with some variability based on the drug. (Suggested reading: Hinkle, J. T., Graziosi, M., Nayak, S. M., & Yaden, D. B. (2024). “Adverse events in studies of classic psychedelics: A systematic review and meta-analysis.” JAMA Psychiatry)

What directions would you recommend for pharmacovigilance?
DBY: Pharmacovigilance in psychedelic research should match the standards applied elsewhere in medical science. In randomized clinical trials, investigators need to comply with established guidelines such as the Consolidated Standards of Reporting Trials (CONSORT). Other study designs should still incorporate systematic methods for detecting and categorizing harms, with protocols specifying how adverse events will be reported, graded for severity and attributed to the intervention. In publications, adverse-event data should be presented clearly. Transparent reporting informs contingency planning for future studies. Pharmacovigilance can be further strengthened by prospectively tracking adverse events of special interest — such as cardiovascular issues, perceptual anomalies, affective instability or behavioral changes.

While the recording and reporting of adverse events in psychedelic science has room for improvement, which we advocate for, it is worth noting that it is above the average across all areas of medical research, so there is room for improvement in clinical science generally. It is possible that some of the innovations we are advancing in psychedelic research could be used to improve other areas as well. (Suggested reading: Ehrenkranz, R., Agrawal, M., Nayak, S. M., & Yaden, D. B. (2024). “Adverse events should not be surprising in psychedelic research.” Psychedelic Medicine)