Selection Bias in Psychedelic Research: Comparing Self-Reported Quality-Of-Life Impact Between Enthusiasts and a General Population Sample
Journal of Psychoactive Drugs March 18, 2026 Jonathan Bendz, Linus Schäfer, David Sjöström et al.
People who are enthusiastic about psychedelics report greater improvements in quality of life from their experiences compared to a general population sample, even after accounting for differences in mindset, setting, motivation, and personality. The study surveyed 1,182 participants (583 enthusiasts and 599 general population) with prior psychedelic use. Enthusiasts scored higher on openness, extraversion, and agreeableness, had more favorable mindsets and settings, and were more motivated by personal growth. Sample membership was the strongest predictor of reported quality-of-life impact, followed by setting, motivation, openness, and mindset. These results clarify how recruiting enthusiasts can inflate reported benefits and highlight the need for representative sampling in psychedelic research.