Drug Effects on Mood and Behavior – Expectancy (MESA-X)
Early Phase I, randomised, placebo-controlled single-session study (n=48) testing a low (13 µg) dose of LSD versus placebo under known versus uncertain drug-identity instructions (balanced placebo design).
Details
This single-session, parallel-group balanced placebo study (N=48) examines pharmacological versus expectancy effects of a marginally detectable LSD dose (13 µg) in healthy volunteers.
Participants are randomised to one of four conditions (Known-Drug; Known-Placebo; Uncertain-Drug; Uncertain-Placebo) and attend a single 4-hour laboratory session; outcomes include subjective and behavioural responses to drug and expectancy manipulations.
The design separates pharmacological effects of microdose LSD from expectancy-driven effects to better understand microdosing claims.