Drug Effects on Mood and Behavior - Expectancy

Conditions

• LSD

Eligibility Criteria

Sex

ALL

Age

18 Years - 40 Years

Healthy Volunteers

Accepted

Interventions

• LSD — DRUG
  The serotonin 2A receptor agonist LSD
• Placebo — DRUG
  Distilled water (0.26 mL)

Study Details

This study will examine the effects of a single low dose of the 5HT2A agonist LSD (Lysergic Acid Diethylamide) (13 µg) or placebo in individuals who are or are not explicitly told what drug they will receive. Although it is known that expectancies strongly influence subjective responses to most drugs, no studies have examined expectancies on response to a very low dose of LSD. This is especially important in the context of 'microdosing' of drugs. People who practice microdosing typically do so with strong expectations of positive effects, making it difficult to determine whether there is a pharmacological effect. To minimize expectancies in the laboratory, participants are usually not told exactly what drug they will receive (i.e., double-blind), but given a range of possibilities. In the present study, the study team will test half the subjects under single-blind conditions, where the participants (but not the research assistant) will know exactly what they are receiving. Other subjects will receive the usual instructions. Healthy volunteers will receive either a marginally detectable dose of LSD (13 micrograms) or placebo, under conditions where they i) know for sure what drug they are receiving or ii) where the identity of the drug is uncertain. Four groups of subjects (N=12 each) will attend single 4-hour laboratory session. The study team will examine subjective and behavioral responses to the drug in each of four conditions (Known-Drug; Known-Placebo; Uncertain-Drug; Uncertain-Placebo).

Key Dates

Start date

Jun 26, 2025

Status verified

Apr 2026

Primary completion

Jun 5, 2026

Completion

Jun 5, 2026

Study Design

Enrollment

48 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

OTHER

Arms

• Experimental: LSD (13 micrograms), Identity of substance known
  LSD tartrate in tasteless solution (0.13 mL). Subjects will receive LSD, and they (but not the research assistant) will be told the identity of the drug.
• Active Comparator: LSD (13 micrograms), Identity uncertain
  LSD tartrate in tasteless solution (0.13 mL). Subjects will be told they might receive a stimulant, sedative, low dose of hallucinogen, or placebo, and will receive LSD.
• Placebo Comparator: Placebo, Identity of substance known
  Distilled water (0.13 mL). Subjects will receive placebo, and they (but not the research assistant) will be told the identity of the drug.
• Placebo Comparator: Placebo, Identity uncertain
  Distilled water (0.13 mL). Subjects will be told they might receive a stimulant, sedative, low dose of hallucinogen, or placebo, and will receive placebo.

Primary Outcome Measure

Visual Analog Scale (VAS) [ Time Frame: During in-lab session: Pre-drug, and every 60 minutes post-drug from 0-4 hours ]

Central Contacts

• Hanna Molla
  7737023560
  [email protected]

Locations (1)

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  EARLY_PHASE1 · Recruiting · University of Chicago · Chicago, Illinois