Acute Dose-dependent Effects of DMT in Healthy Subjects

Phase 1

Completed

• Conditions: Healthy
• Interventions: Drug: N,N-Dimethyltryptamine (162 mg); Drug: N,N-Dimethyltryptamine (108 mg) + dose titration; Drug: N,N-Dimethyltryptamine (54 mg); Drug: N,N-Dimethyltryptamine (108 mg); Drug: N,N-Dimethyltryptamine (216 mg); Drug: Placebo

• Registration Number: NCT05384678
• Lead Sponsor: University Hospital, Basel, Switzerland

Brief Summary

N,N-dimethyltryptamine (DMT) is a psychoactive substance with similar effects such as LSD or psilocybin. However, DMT is less well characterized than the latter substances. The present study is a modern randomized cross-over trial, investigating different continuous intravenous DMT dose rates over a broad dose range. Thus, different doses will be tested and related to subjective and autonomic effects.

Detailed Description

N,N-dimethyltryptamine (DMT) is a naturally-occurring psychedelic substance widely used in recreational and spiritual settings (Ayahuasca). DMT is considered a tool to induce an altered state of consciousness of interest in psychological and psychiatric research. DMT is rapidly metabolized by monoamine oxidase (MAO) A. Therefore, it is inactive when administered orally and has a very short duration of action when administered parenterally (\<20 min). In Ayahuasca, DMT is consumed together with harmala alkaloids that inhibit MAO to increase the oral bioavailablitity of DMT and to prolong its action after oral use. Alternatively, an intravenous administration regime including a bolus and maintenance perfusion has been proposed to induce a stable and prolonged DMT experience and is currently being investigated. However, to date no clinical study has investigated dose-response effects over a broad range of different doses of DMT within the same patient. The aim of the present study is to experimentally test different intravenous DMT doses over a broad dose range and investigate the related subjective and autonomic effects in order to establish a precise dose-response relationship of DMT in healthy subjects.

Study Timeline

• Study First Submitted: 2022-05-17
• Study First Submitted QC: 2022-05-17
• Study First Posted: 2022-05-20
• Study Start: 2022-11-15
• Primary Completion: 2024-03-08
• Study Completion: 2024-03-13
• Status Verified: 2024-04
• Last Update Submitted: 2024-04-24
• Last Update Posted: 2024-04-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 24

Inclusion Criteria

1. Age between 25 and 65 years old
2. Sufficient understanding of the German language
3. Understanding of procedures and risks associated with the study
4. Willing to adhere to the protocol and signing of the consent form
5. Willing to refrain from the consumption of illicit psychoactive substances during the study
6. Abstaining from xanthine-based liquids from the evenings prior to the study sessions and during the sessions
7. Willing not to operate heavy machinery within 6 h of DMT administration
8. Willing to use double-barrier birth control throughout study participation
9. Body mass index between 18-29 kg/m2

Exclusion Criteria

1. Chronic or acute medical condition
2. Current or previous major psychiatric disorder (e.g. psychotic disorders, mania / hypomania, anxiety disorders).
3. Psychotic disorder or bipolar disorder in first-degree relatives
4. Hypertension (SBP>140/90 mmHg) or hypotension (SBP<85 mmHg)
5. Hallucinogenic substance use (not including cannabis) more than 20 times or any time within the previous two months
6. Pregnancy or current breastfeeding
7. Participation in another clinical trial (currently or within the last 30 days)
8. Use of medication that may interfere with the effects of the study medication
9. Tobacco smoking (>10 cigarettes/day)
10. Consumption of alcoholic beverages (>20 drinks/week)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
DMT 1.8 mg/min	N,N-Dimethyltryptamine (162 mg)	-
DMT 1.2 mg/min + dose titration	N,N-Dimethyltryptamine (108 mg) + dose titration	-
DMT 0.6 mg/min	N,N-Dimethyltryptamine (54 mg)	-
DMT 1.2 mg/min	N,N-Dimethyltryptamine (108 mg)	-
DMT 2.4 mg/min	N,N-Dimethyltryptamine (216 mg)	-
Placebo	Placebo	-

Primary Outcome Measures

Name	Time	Method
Subjective effect ratings over time	12 months	Participants will be asked by the investigator to repeatedly rate their subjective effects verbally on a Likert scale from 0 to 10 for: "any drug effect", "good drug effect", "bad drug effect", and "fear". Ratings will be performed before and repeatedly after substance administration and will take approximately 30 sec complete.
Altered states of consciousness profile (5D-ASC)	12 months	5 Dimensions of Altered States of Consciousness (5D-ASC) consisting of 94 items to be rated on a visual analog scale (0-100 mm), with higher values indicating stronger effects with higher scores representing more intense effects.; Assessed once on each study day

Secondary Outcome Measures

Name	Time	Method
Plasma level of BDNF	12 months	Assessed 3 times on each study day
Plasma level of Prolactin	12 months	Assessed 3 times on each study day
Urine recovery of DMT	12 months	Assessed once on each study day
NEO-Five-Factor-Inventory (NEO-FFI)	Baseline	The NEO-FFI is a self-description questionnaire with 60 items for the measurement of the "big five": neuroticism, extraversion, openness, agreeableness, and consciousness. It uses a 5-point Likert scale ranging from "completely disagree" to "fully agree".
Saarbrücker Personality Questionnaire (SPF)	Baseline	The SPF defines empathy as the "reactions of one individual to the observed experiences of another." It assesses 28- items on a 5-point Likert scale ranging from "Does not describe me well" to "Describes me very well". The measure has 4 subscales (Perspective Taking, Fantasy, Empathic Concern, Personal Distress) each made up of 7 different items.
Elliot Humility Scale (EHS)	Baseline	The Elliot Humility Scale (EHS) is a validated 13-item self-rating measure assessing four subscales, i.e. openness, self-forgetfulness, accurate self-assessment, and focus on others on a 5-point Likert scale ranging from "strongly disagree" to "strongly agree"
States of consciousness questionnaire (SCQ)	12 months	Assesses the emergence and intensity of phenomenons occurring in altered states of consciousness on a 6-point Likert scale ranging from 0 ("not at all") to 5 ("extremely") once on each study day
Spiritual Realms Questionnaire	12 months	Assesses the spiritual phenomenons elicited by psychedelic substances through 11 main questions to be answered on a total of 65 sub-ordered 100mm visual analog scales once on each study day
Blood pressure	12 months	Assessed 20 times on each study day via systolic and diastolic blood pressure
heart rate	12 months	Assessed 20 times on each study day via heart rate
body temperature	12 months	Assessed 20 times on each study day via tympanic body temperature
Plasma level DMT	12 months	Assessed 22 times on each study day
Plasma level of oxytocin	12 months	Assessed 3 times on each study day
Plasma level of cortisol	12 months	Assessed 3 times on each study day

Trial Locations

Locations (1)

Universtity Hospital Basel; 🇨🇭 Basel, Switzerland