Expecting a stimulant changed reported feelings more consistently than cognitive test results
In a placebo experiment with college students, choosing whether to take the supposed drug did not clearly change its subjective or cognitive effects.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Students who believed they had taken a stimulant reported enhanced mood and drug effects compared with students who did not expect a drug. Objective cognitive tests mostly showed no placebo effect, apart from a specific reaction-time result. Allowing students to choose whether to take the placebo did not clearly alter the subjective effects or cognitive performance.
The sample was demographically narrow, and the abstract does not report assessment timing or detailed cognitive effect estimates. Because the supposed stimulant was placebo, these results do not estimate the effects of an active stimulant.
What researchers found
Objective cognitive task performance
Expected stimulant versus no expected drug, after the experimental assignment; one reaction-time index was an exception. Exact assessment timing was not reported.
What choice added
The experiment separated the opportunity to choose from the expectation of receiving a drug. Students who took the supposed stimulant actually received placebo, allowing researchers to examine responses to that expectation.
Feelings and task results differed
Feeling a mood or drug effect did not consistently coincide with better task performance. The isolated reaction-time finding also means the cognitive results should not be described as uniformly null.
The original publication
To choose or not to choose: Examining the influence of choice on elicitation of subjective and objective prescription stimulant placebo effects in the laboratory.
Looby A, Berry KA, Petrey AM et al.
Exp Clin Psychopharmacol · 2026
- PubMed ID
- 41411020
- Record checked
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