The International Journal of Neuropsychopharmacology
March 12, 2020
Erwin Krediet, Tijmen Bostoen, Joost J. Breeksema et al.
262 citations
Posttraumatic stress disorder (PTSD) often remains chronic after psychotherapy, and few effective medications exist. A promising new approach involves psychedelic drugs. This review discusses four compound types: MDMA, ketamine, classical psychedelics (psilocybin, LSD), and cannabinoids. It describes each compound's therapeutic rationale, administration setting, and current evidence for treating PTSD. Each offers unique qualities, from rapidly targeting symptoms to facilitating psychotherapy. The review outlines questions for future research.
Journal of Psychopharmacology
August 26, 2022
Joost J. Breeksema, Bouwe Kuin, Jeanine Kamphuis et al.
171 citations
A systematic review of 44 clinical studies (34 quantitative, 10 qualitative) involving 598 patients treated with MDMA or serotonergic psychedelics (psilocybin, LSD, ayahuasca) found that treatments were generally well tolerated, though adverse events were often not systematically assessed. Common acute adverse events across diagnoses and compounds included nausea, headaches, and anxiety. Late adverse events included headaches (psilocybin, MDMA), fatigue, low mood, and anxiety (MDMA). One serious adverse event occurred during MDMA administration (increased premature ventricular contractions requiring brief hospitalization); no other events required medical intervention. Qualitative studies suggested that psychologically challenging experiences may be therapeutically beneficial. The authors conclude that adverse events are poorly defined and likely underreported due to study design and sample selection.
ACS Pharmacology & Translational Science
July 16, 2021
Joost J. Breeksema, Michiel van Elk
69 citations
The authors argue that the concept of mystical experience should remain central to psychedelic science, countering a recent call to abandon it. They emphasize the need to recognize the diversity and strangeness of psychedelic experiences, drawing on a rich tradition and scientific tools for studying mystical-type experiences. These experiences are relevant for understanding the therapeutic effects of psychedelics. The authors also call for greater diversity in both the types of experiences and the participants included in future research.
Scientific Reports
February 5, 2024
Alistair Niemeijer, Erwin Krediet, Jeanine Kamphuis et al.
50 citations
Patients with treatment-resistant depression who received psilocybin in a clinical trial described challenges with trust-building and expectation management, the need to navigate intense experiences often guided by music, and a desire for a more comprehensive treatment including multiple psilocybin sessions and sustained therapy. Distrust in mental healthcare generally, but trust in study therapists, was a key subtheme. The findings suggest that optimizing psilocybin treatment for this population requires individualized preparation, investment in trust-building, additional sessions, and access to ongoing psychotherapy with trusted therapists.
Psychiatr Res Clin Pract
February 11, 2025
Jules Evans, Marc Aixalà, Brian T. Anderson et al.
18 citations
Thirty psychedelic researchers identified critical gaps in knowledge about harms from psychedelic use, including how to define those harms, predict them, and treat them effectively. They recommend better online information, peer support groups, affordable therapy, and psychiatric consultation for people experiencing post-psychedelic difficulties. The researchers also call for improved funding for a psychedelic safety net, suggesting that psychedelic philanthropists, investors, and companies commit 1% of their investment to support safety measures such as research and support services. The article outlines practical steps to make the field of psychedelic medicine safer.
Psychedelics
June 28, 2026
Joost J. Breeksema, Ulf Bremberg, Jens H. van Dalfsen et al.
Psychedelic therapies face layered complexity from interactions between pharmacological and extra-pharmacological factors, and their embeddedness in societal, legal, and regulatory systems. This is compounded by epistemic fragmentation: dominant biomedical paradigms often clash with knowledge from social sciences, humanities, or Indigenous traditions. Though interdisciplinary engagement is increasingly recognized as necessary, existing calls rarely specify structural or pedagogical conditions for operationalizing it. Addressing these complexities requires moving beyond superficial collaboration; genuine interdisciplinary progress needs researchers capable of productive friction across epistemic cultures. The authors propose cultivating T-shaped competencies and intersectoral training as a structural response to these systemic challenges.