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. 2025 Feb 27;3(1):48-52.
doi: 10.1089/psymed.2024.0002. eCollection 2025 Mar.

The Antidepressant Effects of Vaporized N, N-Dimethyltryptamine: An Open-Label Pilot Trial in Treatment-Resistant Depression

Marcelo Falchi-Carvalho  1   2 , Handersson Barros  1   3 , Raynara Bolcont  1 , Sophie Laborde  1   3 , Isabel Wießner  1 , Sérgio Ruschi B Silva  1 , Daniel Montanini  1   4 , David C Barbosa  1   5 , Ewerton Teixeira  1 , Rodrigo Florence-Vilela  1 , Raissa Almeida  1   6 , Rosana K A de Macedo  1   6 , Flávia Arichelle  1 , Érica J Pantrigo  1 , José V Costa-Macedo  1   3 , Emerson Arcoverde  5 , Nicole Galvão-Coelho  1   6 , Draulio B Araujo  1   3   5 , Fernanda Palhano-Fontes  1   5
Affiliations

The Antidepressant Effects of Vaporized N, N-Dimethyltryptamine: An Open-Label Pilot Trial in Treatment-Resistant Depression

Marcelo Falchi-Carvalho et al. Psychedelic Med (New Rochelle). .

Abstract

Introduction: N,N-Dimethyltryptamine (DMT), a naturally occurring psychedelic tryptamine contained in the indigenous ayahuasca brew, has shown antidepressant effects. This open-label clinical trial investigates for the first time the efficacy of vaporized DMT in treatment-resistant depression (TRD).

Methods: Six TRD patients participated in an open-label, fixed-order, dose-escalation study, receiving a lower (15 mg) and then a higher (60 mg) dose of vaporized DMT in a single-day session. Depression severity was assessed using the Montgomery-Asberg depression rating scale (MADRS) and the Patient Health Questionnaire-9 (PHQ-9) up to one month post-dosing.

Results: Significant reductions in MADRS and PHQ-9 scores were noted from Day 1 to Month 1 (M1). The mean MADRS score variation from baseline to Day 7 (D7) was -22 points and -17 points at M1. PHQ-9 scores also showed significant decreases, mirroring the MADRS results. By D7, 83.33% of patients responded to treatment, with 66.67% achieving remission. At M1, 66.67% maintained response, and 50% maintained remission.

Discussion: The rapid onset and sustained antidepressant effects of vaporized DMT align with the paradigm of rapid-acting antidepressants to be used in the scope of interventional psychiatry. The noninvasive route and short-acting nature of DMT offer practical advantages, potentially enhancing accessibility to psychedelic treatments.Clinical Trial Registration: Clinicaltrials.gov NCT06094907.

Keywords: DMT; N,N-Dimethyltryptamine; depression; psychedelic; treatment-resistant depression.

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