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Adverse events in clinical treatments with serotonergic psychedelics and MDMA: A mixed-methods systematic review

Joost J. Breeksema, Bouwe Kuin, Jeanine Kamphuis, Wim van den Brink, Eric Vermetten, Robert A Schoevers

Journal of Psychopharmacology August 26, 2022 DOI: 10.1177/02698811221116926 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Systematic review Qualitative Peer reviewed
Sample size 598
Population Patients in clinical trials with MDMA or serotonergic psychedelics
Interventions MDMA psilocybin lysergic acid diethylamide ayahuasca
Topics MDMA Serotonin
Keywords Adverse effect Hallucinogen Pharmacology
Citations 171
Key findings Treatments with MDMA and serotonergic psychedelics were generally well tolerated, but adverse events are poorly defined and likely underreported due to lack of systematic assessment and sample selection.

Abstract

Introduction: Small-scale clinical studies with psychedelic drugs have shown promising results for the treatment of several mental disorders. Before psychedelics become registered medicines, it is important to know the full range of adverse events (AEs) for making balanced treatment decisions.

Objective: To systematically review the presence of AEs during and after administration of serotonergic psychedelics and 3,4-methyenedioxymethamphetamine (MDMA) in clinical studies.

Methods: We systematically searched PubMed, PsycINFO, Embase, and ClinicalTrials.gov for clinical trials with psychedelics since 2000 describing the results of quantitative and qualitative studies.

Results: We included 44 articles (34 quantitative + 10 qualitative), describing treatments with MDMA and serotonergic psychedelics (psilocybin, lysergic acid diethylamide, and ayahuasca) in 598 unique patients. In many studies, AEs were not systematically assessed. Despite this limitation, treatments seemed to be overall well tolerated. Nausea, headaches, and anxiety were commonly reported acute AEs across diagnoses and compounds. Late AEs included headaches (psilocybin, MDMA), fatigue, low mood, and anxiety (MDMA). One serious AE occurred during MDMA administration (increase in premature ventricular contractions requiring brief hospitalization); no other AEs required medical intervention. Qualitative studies suggested that psychologically challenging experiences may also be therapeutically beneficial. Except for ayahuasca, a large proportion of patients had prior experience with psychedelic drugs before entering studies.

Conclusions: AEs are poorly defined in the context of psychedelic treatments and are probably underreported in the literature due to study design (lack of systematic assessment of AEs) and sample selection. Acute challenging experiences may be therapeutically meaningful, but a better understanding of AEs in the context of psychedelic treatments requires systematic and detailed reporting.

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