Fixed Order, Open-Label, Dose-Escalation Study of DMT in Humans

The goal of this fixed order, open-label, dose-escalation study is to investigate the safety and efficacy of specific doses of dimethyltryptamine (DMT) in humans.

The results of this study will inform the doses to be used in a larger, double-blind, randomized, placebo-controlled, crossover study. Since the goal of the open label study is to inform the double-blind, randomized, placebo-controlled study, the investigators are citing the hypothesis of the latter solely for providing context. The investigators hypothesize that the administration of DMT will result in neuroplastic changes in healthy and depressed subjects. These changes in neuroplasticity will be indexed using electroencephalographic (EEG) measures and tasks. These neuronal changes may in parallel cause changes in mood measured both in healthy and depressed subjects, which will be captured using appropriate psychometric measures of mood.

Healthy individuals and patients with major depressive disorder will participate in this study. Subjects will receive 0.1 mg/kg and 0.3 mg/kg DMT in a fixed order across 2 test days.

Systolic and diastolic blood pressure will be measured before and several times after the administration of DMT on each test day.

-60 and -30 minutes before DMT administration; 0, +5, +10, +15, +20, +30, +45, +60, and +120 minutes after DMT administration

Heart rate will be measured before and several times after the administration of DMT on each test day.

-60 and -30 minutes before DMT administration; 0, +5, +10, +15, +20, +30, +45, +60, and +120 minutes after DMT administration

The modified Altered States of Consciousness Rating Scale (ASC) will be used to assess drug-induced altered states of consciousness before and several times after drug administration. This is a 23-item subjective rating scale that will be completed using a visual analog scale format. Questions are scored 0 to 100 each; higher numbers indicate greater psychedelic effects.

Anxiety will be assessed using a visual analog scale that subjects will be asked to score from 0 (not at all) to 100 (worst ever) to capture the net anxiety produced by DMT. This will be collected before and several times after DMT administration.

Subjects will be asked to answer questions such as (1) How likely are you to use this drug? and (2) How much are you willing to pay for this experience? using a visual analog scale.

Overall tolerability will be assessed using a visual analog scale that subjects will be asked to score from 0 (well tolerated) to 100 (intolerable) to capture the net tolerability of DMT.

Healthy controls inclusion criteria: Medically healthy Psychiatrically healthy Healthy controls exclusion criteria: Unstable medical conditions Psychiatric illness Depression inclusion criteria: Medically healthy Diagnosis of major depressive disorder Depression exclusion criteria: -Unstable medical conditions