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Exploratory study of the dose-related safety, tolerability, and efficacy of dimethyltryptamine (DMT) in healthy volunteers and major depressive disorder.

Deepak Cyril D'Souza, Shariful A. Syed, L Taylor Flynn, Hamideh Safi-Aghdam, Nicholas V. Cozzi, Mohini Ranganathan

Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology September 1, 2022 DOI: 10.1038/s41386-022-01344-y (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Open-label, fixed-order, dose-escalation exploratory phase 1 study Pilot study Peer reviewed
Sample size 10
Population Treatment-resistant individuals with major depressive disorder (MDD) and healthy controls
Intervention Intravenous DMT
Dose 0.1 mg/kg followed by 0.3 mg/kg
Topics Depression Psychedelic-assisted therapy 5-MeO-DMT DMT
Keywords Rapid-onset psychedelic Potent compound Hallucinogens Psychotropic drugs Entheogens Depression treatment Antidepressant effects Mood improvements Mood disorders Clinical research Researchers explored Well-tolerated Positive results Drug development Medical research Safety studies Efficacy studies Clinical trials Mental health Therapeutic potential Well-being Psychological health Behavioral health
Citations 156
Key points Intravenous DMT at 0.3 mg/kg was associated with a significant next-day reduction in depression scores in treatment-resistant MDD patients.

Abstract

There is considerable interest in the therapeutic potential of psychedelic drugs. Dimethyltryptamine (DMT) is a potent, rapid-onset, and short-acting psychedelic drug that has not yet been independently tested for the treatment of depression. The safety, tolerability, and efficacy of intravenous DMT were investigated in treatment-resistant individuals with major depressive disorder (MDD) and healthy controls (HC) in an open-label, fixed-order, dose-escalation (0.1 mg/kg followed by 0.3 mg/kg) exploratory phase 1 study that was conducted in a typical hospital setting with strategic psychoeducation/support, but minimal psychotherapy. Tolerability, safety, cardiovascular function, abuse liability, psychedelic, and psychotomimetic effects, mood, and anxiety were assessed at each dosing session. In addition, depression was measured using the HAMD-17 in MDD participants 1 day after each dosing session. DMT was tolerated by both HC (n = 3) and MDD participants (n = 7) studied; there were no dropouts. HAMD-17 scores decreased significantly (p = 0.017) compared to baseline in MDD participants the day after receiving 0.3 mg/kg DMT (mean difference -4.5 points, 95% CI: -7.80 to -1.20, Hedge's g = 0.75). Adverse events were mostly mild with one self-limited serious event. DMT increased blood pressure, heart rate, anxiety, psychedelic effects, and psychotomimetic effects, which resolved within 20-30 min of injection. There were no dose-related differences in measures of drug reinforcement and abuse liability. In this small exploratory pilot study, intravenous DMT at doses of 0.1 and 0.3 mg/kg was mostly safe and tolerated and may have next-day (rapid) antidepressant effects in patients with treatment-resistant MDD. Further rigorous trials are warranted to replicate these findings and to determine the durability of antidepressant effects.

In the evidence

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

  • Intravenous DMT at 0.3 mg/kg was associated with a significant next-day reduction in HAMD-17 depression scores in treatment-resistant MDD patients.

    Synthesized

Comparable studies

Other non-randomized and open-label trials on DMT for depression, most cited first.

Study Year Design Participants
A phase 1/2 trial to assess safety and efficacy of a vaporized 5-methoxy-N,N-dimethyltryptamine formulation (GH001) in patients with treatment-resistant depression Adult patients with treatment-resistant depression 2023 Phase 1/2 clinical trial n = 16
Rapid and sustained antidepressant effects of vaporized N,N-dimethyltryptamine: a phase 2a clinical trial in treatment-resistant depression. Patients with treatment-resistant depression 2025 Open-label trial n = 14
The Antidepressant Effects of Vaporized N,N-Dimethyltryptamine: An Open-Label Pilot Trial in Treatment-Resistant Depression. Patients with treatment-resistant depression 2025 Open-label clinical trial n = 6
The antidepressant effects of vaporized N,N-Dimethyltryptamine: a preliminary report in treatment-resistant depression Patients with treatment-resistant depression 2024 Open-label, fixed-order, dose-escalation study (Phase 2a clinical trial) n = 6
Beyond symptom reduction: DMT improves anxiety, life satisfaction, and quality of life in healthy volunteers and patients with depression Healthy individuals and patients with treatment-resistant depression 2026 Open-label clinical trial n = 41

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