Comparing the effects of LSD, psilocybin, and DMT on consciousness in healthy individuals

Direct Comparison of Altered States of Consciousness Induced by LSD, Psilocybin, and DMT in a Randomized, Placebo-controlled, Cross-over Trial in Healthy Participants (LPD-Study)

This study is testing how three different psychedelics—LSD, psilocybin, and DMT—affect people's consciousness to see how they compare in healthy individuals.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 24 (estimated)
• Ages: 25 Years and up
• Sex: All
• Sponsor: University Hospital, Basel, Switzerland (Academic / other)
• Locations: 1 site (Basel)
• Trial ID: NCT06899334 on ClinicalTrials.gov

What this trial studies

This study aims to compare the effects of three psychedelics—LSD, psilocybin, and DMT—on consciousness in healthy participants. By administering equivalent doses of each substance while standardizing the duration of effects with ketanserin, the researchers will evaluate the qualitative similarities and differences in the peak experiences induced by these hallucinogens. The study is designed to ensure blinding and control for pharmacokinetic differences, making it a unique direct comparison of these substances. Participants will undergo a series of assessments to measure the acute and subacute effects of each psychedelic.

Who should consider this trial

Good fit: Ideal candidates are healthy individuals aged 18-65 with a good understanding of the German language and no history of major psychiatric disorders.

Not a fit: Patients with chronic medical conditions or a history of psychiatric disorders may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance our understanding of psychedelics and their therapeutic potential for treating psychiatric disorders.

How similar studies have performed: While there have been studies on LSD and psilocybin, this direct comparison with DMT is novel and has not been extensively tested.

Eligibility criteria

Inclusion Criteria:

1. Good understanding of the German language
2. Understanding of procedures and risks associated with the study
3. Willing to adhere to the protocol and signing of the consent form
4. Willing to refrain from the consumption of illicit psychoactive substances during the study
5. Willing not to operate heavy machinery within 48 h after administration of a study substance
6. Willing to use effective birth control throughout study participation
7. Body mass index 17 - 34.9 kg/m2

Exclusion Criteria:

1. Relevant chronic or acute medical condition
2. Current or previous major psychiatric disorder (e.g. psychotic disorder)
3. Psychotic disorder or bipolar disorder in first-degree relatives
4. Hypertension (SBP\>140/90 mmHg) or hypotension (SBP\<85 mmHg)
5. Bradycardia (\< 45 bpm)
6. Prolonged QTc interval (males: \>450 ms, females: \>470 ms)
7. AV block II° (Mobitz type and Webckebach type) and III°
8. Hallucinogenic substance use (not including cannabis) more than 20 times or any time within the previous two months
9. Pregnancy or current breastfeeding
10. Participation in another clinical trial (currently or within the last 30 days)
11. Use of medication that may interfere with the effects of the study medication
12. Tobacco smoking (\>10 cigarettes/day)
13. Excessive consumption of alcoholic beverages (\>15 drinks/week)

Where this trial is running

Basel

• University Hospital — Basel, Switzerland (Recruiting)

Study contacts

• Principal investigator: Matthias E Liechti, Prof. Dr. MD — University Hospital, Basel, Switzerland
• Study coordinator: Matthias E Liechti, Prof. Dr. MD

Conditions Healthy; Psychedelics; LSD; Psilocybin; DMT