A study comparing psychedelic enthusiasts and people from the general population (who also had psychedelic experiences) found that the enthusiasts tended to report much greater positive quality-of-life effects. The enthusiasts also showed higher openness, extraversion, and agreeableness. This indicates that recruitment strategies in psychedelic research that lean towards including enthusiasts may shape the outcomes obtained in those studies. The paper was published in the Journal of Psychoactive Drugs.
Psychedelic drugs are substances that can strongly alter perception, mood, thinking, and the sense of self. They may change how people experience colors, sounds, time, memories, emotions, and the meaning of events. Classic psychedelics include LSD, psilocybin from “magic mushrooms,” DMT, and mescaline. These substances mainly act on serotonin receptors in the brain.
In research settings, psychedelics are being studied for possible therapeutic use in conditions such as depression, PTSD, anxiety, and substance use disorders. Their effects depend heavily on dose, personality, expectations, mental state, physical setting, and social support. Psychedelics can also carry risks, including panic, confusion, dangerous behavior during intoxication, worsening of some psychiatric conditions, and legal consequences where they are prohibited.
Study author Jonathan Bendz and his colleagues noted that many studies of psychedelic users report extraordinarily positive self-reported effects. However, they suggest that this might represent an exaggeration of the real effects caused by biased selection, or even self-selection, of study participants. The issue is that the effects of psychedelics can only be tested on individuals who agree to use them. These participants tend to be individuals who have already had especially positive experiences with psychedelic use.
To examine this hypothesis, these researchers conducted a study comparing whether the self-reported quality-of-life impact of psychedelic experiences differed between a convenience sample of psychedelic enthusiasts and a group of people from the general population recruited via Prolific. They also wanted to see whether the difference between the two groups remained after controlling for mindset, setting, motivation to use psychedelic drugs, and personality traits.
The enthusiast group consisted of 583 individuals recruited through an anonymous survey posted on the Facebook and Instagram pages of a Swedish nonprofit organization that disseminates information about psychedelic science (Nätverket för Psykedelisk Vetenskap). A snowball sampling approach was used to reach more participants. The general population group consisted of 599 individuals recruited via Prolific (an online survey platform). They were required to have prior psychedelic experience, but were not recruited from a specific psychedelic community.
Study participants completed assessments of the quality-of-life impact of their psychedelic experiences (e.g., “How has your most meaningful psychedelic experience affected the quality of your relationship with… family, friends, yourself, society, and nature?”). They also answered questions regarding their mindset and physical setting during the experience (“To what extent did you experience your mindset/environment to be optimal?”), their motivation (“What was your motivation for using a psychedelic substance?”), and their personality (using the IPIP-NEO-30 assessment).
Results showed that the psychedelic enthusiasts tended to report a much higher quality-of-life impact from their psychedelic experiences compared to the Prolific group. The enthusiast group also reported having a more optimal mindset and setting during their trips, and they were more likely to report taking the drugs for personal growth rather than for fun. Finally, the enthusiasts tended to be more open to new experiences, extraverted, and agreeable than the participants from the Prolific group.
Even after using a statistical model to account for these differences in personality, mindset, setting, and motivation, simply belonging to the enthusiast group remained the strongest predictor of reporting a high quality-of-life impact.
“As expected, participants recruited from an enthusiast-leaning channel reported considerably greater benefits [of psychedelic use] than those recruited from a general-population platform. Even after controlling for mindset, setting, motivation, and personality, sample membership remained the strongest predictor of quality-of-life impact,” the study authors concluded.
“The persistent effect of sample membership suggests that the two groups differ in additional ways not captured by our measures, for example in cultural expectations, social context, or demographic composition, shaping reported outcomes. These results underscore the need for caution when interpreting findings from psychedelic studies that rely on highly engaged user populations.”
The study sheds light on important methodological issues that studies of psychedelic effects face. However, the authors note some limitations. For example, the two groups had demographic differences; the general sample was overwhelmingly from the United States, while the enthusiast sample lacked country-of-residence data for most participants (though a portion resided in Sweden). This introduces the possibility of cross-cultural differences influencing the results.
Additionally, it should be noted that the Prolific sample likely included many psychedelic enthusiasts as well. Because of this, the difference between the two groups in this study likely underestimates the true difference between the general population and psychedelic enthusiasts.
The paper, “Selection Bias in Psychedelic Research: Comparing Self-Reported Quality-Of-Life Impact Between Enthusiasts and a General Population Sample,” was authored by Jonathan Bendz, Linus Schäfer, David Sjöström, Sverker Sikström, and Petri Kajonius.
