Registered clinical studies investigating psychedelic drugs for psychiatric disorders

This review (2021) summarizes the study characteristics of all ongoing registered clinical trials investigating psychedelic drugs for psychiatric disorders and identifies that their majority focuses on investigating MDMA and psilocybin for treating depression or PTSD, while only 30% of their results are published.


Introduction: Psychedelics are a hallucinogenic class of psychoactive drugs with the primary effect of activating non-ordinary states of consciousness. Due to the positive preliminary findings of these drugs in the treatment of psychiatric disorders, the number of registered clinical studies has risen significantly.

Methods: In this paper, clinical studies registered on that evaluate the treatment of any psychiatric disorder with psychedelics (excluding ketamine) are summarized and analyzed. 70 registered studies were identified from a search on December 3, 2020.

Results: The majority of studies aim to investigate methylenedioxymethamphetamine (MDMA) (45.7%) and psilocybin (41.4%). Studies evaluating ayahuasca, lysergic acid diethylamide (LSD), ibogaine hydrochloride, salvia divinorum, 5-MeO-DMT and DMT fumarate were less common at 1.4%, 4.2%, 2.8%, 1.4%, 1.4% and 1.4% of total registered studies, respectively. Most of the studies on MDMA, psilocybin, ayahuasca and salvia divinorum investigated their therapeutic effect on post-traumatic stress disorder (PTSD) and major depressive disorder (MDD). LSD was investigated for MDD, anxiety, and severe somatic disorders and ibogaine hydrochloride was investigated for substance and alcohol use disorders. 5-MeO-DMT and DMT fumarate were both investigated for MDD. Only 21/70 registered studies had published results with the majority not yet completed.

Discussion: In view of the large number of ongoing studies investigating psychedelics, it is imperative that these studies are considered by researchers and stakeholders in deciding the most relevant research priorities for future proposed studies.”

Authors: Ashley N. Siegel, Shakila Meshkat, Katie Benitah, Orly Lipsitz, Hartej Gill, Leanna M. W Lui, Kayla M. Teopiz, Roger S. McIntyre & Joshua D. Rosenblat


We are currently in the ‘third wave’ of psychedelics research. The first wave being the traditional use and/or the research that was done before the second half of the 20th century. The second wave was the research in the 1960s and ’70s. The current, third, wave is the research (and investments) that have started around the turn of the century.

This review article takes a bird-eye view of the current state of research and identifies which clinical trials are ongoing. The study looked at different psychedelics but has chosen to exclude ketamine from the results. Studies were included that were recruiting, active, or already completed. Most studies looked at treatment (of mental health disorders), whilst a smaller percentage conducted basic science.

What the review found

  • Most studies are being done with MDMA and psilocybin (together 87%)
  • Most studies are investigating psychedelics or psychedelic-assisted therapy for depression (MDD) and PTSD
  • Of the 70 studies identified, only 21 had published their results as of March 2021

As expected, most trials were being done last year, and we can expect even more this year. As can be seen on this tracker, the amount of studies that is registered has been increased even further with 36 studies already registered (excluding ketamine studies).

The authors of the study recommend that future trials put more effort into discovering which protocols work best. This is both with regards to dosing and to the forms of therapy used. This way we can put more effort into finding what will be the most cost-effective or efficient way of providing psychedelic-assisted therapy for a whole range of mental health disorders.

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Registered clinical studies investigating psychedelic drugs for psychiatric disorders

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Published in
Journal of Psychiatric Research
May 28, 2021
0 citations

Study details

Topics studied
Anxiety Pain Addiction

Study characteristics
Literature Review

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