Registered clinical studies investigating psychedelic drugs for psychiatric disorders.

Abstract

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

In the evidence

This study is part of the evidence base for 4 syntheses in the library. Here is how each one recorded it.

• State of the evidence: Ayahuasca for depression ?Unclear

  As of December 2020, 70 registered trials studied psychedelics for psychiatric disorders, with ayahuasca among the less common agents and only 21 studies having published results.

  Synthesized October 22, 2026

• State of the evidence: DMT for depression ?Unclear

  Only a small fraction of registered psychedelic trials involved DMT or 5-MeO-DMT (each about 1.4%), both targeting MDD, and only 21 of 70 registered studies had published results.

  Synthesized October 22, 2026

• State of the evidence: LSD for depression ?Unclear

  As of December 2020, 70 registered trials investigated psychedelics for psychiatric disorders, with LSD studied for MDD, anxiety, and severe somatic disorders, but only 21 had published results.

  Synthesized October 22, 2026

• State of the evidence: MDMA for PTSD ?Unclear

  Reports that most registered psychedelic trials study MDMA or psilocybin for PTSD and depression, but only 21 of 70 had published results.

  Synthesized October 22, 2026

Comparable studies

Other narrative reviews on DMT for depression, most cited first.