Transformative experience and social connectedness mediate the mood-enhancing effects of psychedelic use in naturalistic settings

Forstmann and colleagues situate their study within a renewed scientific interest in the therapeutic and psychological effects of serotonergic psychedelics (for example, psilocybin and LSD). They note that controlled laboratory work and large-scale surveys have reported positive effects on mood, well-being and social attitudes, but that both approaches have limitations: laboratory studies often have small samples and artificial settings that do not reflect typical use, while retrospective surveys risk recall bias and demand effects. The authors emphasise the importance of "set and setting"—the influence of intrapersonal and environmental context on psychedelic effects—and argue that evidence from naturalistic settings is scarce and needed to understand how these substances affect mood and social connectedness in everyday use. To address this gap, the study asked whether recent psychedelic use at multiday mass gatherings predicts positive mood and whether two psychological processes—self-reported transformative experience (TE) and increased social connectedness—explain that relationship. The researchers preregistered hypotheses and designed a field study to compare very recent (past 24 h) versus moderately recent (past week) psychedelic use, while controlling for use of other psychoactive substances and demographic covariates, thereby aiming to capture acute and postacute effects with greater ecological validity than prior work.

Data were collected between 2015 and 2017 from attendees at six multiday mass gatherings in the United States and the United Kingdom. Across three years, 1,242 people completed the on-site questionnaire; 17 participants were excluded because they failed an attention/sobriety check, yielding a final sample of 1,225. Recruitment took place at booths labelled "Play Games for Science," and participants completed tablet or paper surveys after providing informed consent. To discourage repeat participation and enable anonymised linkage, participants generated a short ID code; the protocol had university ethics approval. Participants received small practical prizes as compensation. Recent use of psychoactive substances was assessed for multiple substance classes (including alcohol, nicotine, cannabis products, hallucinogens/psychedelics, euphorics such as MDMA, stimulants, narcotic analgesics, benzodiazepines, inhalants, and others). For each class, participants reported use within the past 24 h, use during the past week, whether they were currently under the influence, and whether it was a first-time use that week. The survey incorporated legal examples within each class to reduce underreporting. The primary predictor variables were binary indicators coded 1 if the participant had used any substance in the class within the past week or was currently under influence, and 0 otherwise; a separate set of variables distinguished very recent (past 24 h/current) from moderately recent (week prior) use. Preregistered control variables included age, gender (three-category dummy coding), educational attainment (dummy-coded levels), religiosity (seven-point scale), and political orientation (seven-point liberal–conservative scale). Transformative experience (TE) was measured with a single seven-point Likert item asking whether the participant had a TE at the event; a narrower epistemic transformative experience (ETE) was defined and assessed with a similar item and additional follow-up questions about extent, valence, expectation, desire, and moral change. Social connectedness was measured with an adapted ‘‘inclusion of others in the self’’ pictorial scale comprising seven circles with varying overlap, and positive mood was assessed with a single pictorial item of six faces ranging from joyful to crying. The authors preregistered hypotheses that recent psychedelic use would predict TEs and social connectedness and that TEs would mediate any relationship between psychedelic use and positive mood. Analyses were conducted in R using the lavaan package with maximum likelihood estimation and full-information maximum likelihood to handle missing data. Regression models included all substance-class indicators plus covariates; the team also ran exploratory structural equation models (SEMs) to examine sequential mediation.

The sample was relatively young (mean age 32.39, SD = 11.37), well educated (median: four-year college degree), with low-to-moderate religiosity (mean = 2.31 on a seven-point scale) and moderate liberal political orientation. Substance use prevalence among attendees was: alcohol 80.0%, cannabis products 50.9%, nicotine 35.9%, and psychedelic substances 26.6%; 12.3% reported no substance use. In regression analyses controlling for other substance classes and demographic covariates, recent use of psychedelic substances positively predicted self-reported TEs: b = 0.79 (β = 0.17), SE = 0.15, P < 0.001, 95% CI [0.49, 1.09]. This association remained significant after adding participants' desire for and expectations about TEs to the model (b = 0.67, β = 0.14, P < 0.001). ETEs were less common but also positively predicted by recent psychedelic use (b = 0.46, β = 0.10, SE = 0.15, P = 0.002), and that effect persisted when controlling for desire/expectation. Among participants reporting a TE, those who had taken psychedelics rated their experiences as more positive (mean = 5.44 vs 4.87) and greater in extent (mean = 4.05 vs 3.24), and more likely to report moral value change, with all comparisons statistically significant. Psychedelic use predicted higher positive mood: b = 0.14 (β = 0.08), SE = 0.06, P = 0.019. Self-reported TE strongly predicted positive mood (b = 0.08, β = 0.21, SE = 0.01, P < 0.001), and the indirect effect of psychedelics on mood via TE was significant (b = 0.05, SE = 0.01, P < 0.001), rendering the direct effect of psychedelics on mood nonsignificant after mediation. Social connectedness was also predicted by recent psychedelic use (b = 0.36, β = 0.10, SE = 0.12, P = 0.003) and in turn predicted positive mood (b = 0.11, β = 0.23, SE = 0.01, P < 0.001). The indirect effect of psychedelics on mood via social connectedness was significant (b = 0.04, SE = 0.01, P = 0.007), and the remaining direct effect of psychedelics on mood was reduced to marginal significance (P = 0.089). When separating very recent (past 24 h/current) from moderately recent (week prior) psychedelic use, most psychedelic users (69.6%) reported use in the last 24 h, and very recent use primarily drove the associations with TEs, ETEs and positive mood. Comparisons showed significantly greater predictive power for 24 h use versus week-prior use for TEs (Δb = 0.58, P = 0.017), for ETEs (Δb = 0.49, P = 0.035), and for positive mood (Δb = 0.27, P = 0.005). Moderately recent use did not uniquely predict the outcomes in the models. A structural equation model testing sequential mediation (very recent psychedelic use → TE → social connectedness → positive mood) fit the data well and indicated that very recent psychedelic use predicted positive mood predominantly via self-reported TEs and, to a lesser extent, via increased social connectedness. Sensitivity checks excluding participants who reported being currently under the influence (n = 47) or excluding all participants under any substance produced similar effect sizes. Controlling for days attended at the event (median 3 days) did not alter the main pattern of results.

The investigators interpret their findings as evidence that recent psychedelic use in naturalistic, multiday mass gathering settings is associated with increased reports of transformative experience, greater social connectedness and enhanced positive mood. They emphasise that higher TE reports among psychedelic users were not explained away by participants' prior desire for or expectation of transformation, and that users judged their TEs to be more positive, more intense and more likely to entail moral-value change compared with nonusers who reported TEs. Positioning these results relative to prior work, the authors argue that the field design captures postacute psychological effects while avoiding some limitations of laboratory and retrospective survey work—namely small samples, artificial settings, recall bias and demand characteristics. The finding that very recent (past 24 h) use had stronger associations than moderately recent (week prior) use highlights the role of temporal proximity or salience in reported TEs, connectedness and mood; the authors suggest this may reflect a temporal decline in effect, lower statistical power for the less common moderately recent group, or a need for longer-term integration for lasting change to emerge. They also note that euphorics such as MDMA did not meaningfully predict the outcomes, which they find notable given MDMA's prototypical association with sociability. The paper acknowledges important limitations: substance use was self-reported, so exact substances and doses could not be verified; unmeasured confounders or personality variables may influence both willingness to use psychedelics and propensity to report TEs; the festival-attending sample may not generalise to the broader population; and the observational design precludes definitive causal inference. The authors argue, however, that the stronger effects for very recent use provide some support for a causal interpretation running from substance use to psychological outcomes. They conclude that laboratory-in-the-field studies like theirs can complement placebo-controlled trials to build a fuller understanding of how psychedelics affect mood and social relationships, and they recommend longitudinal and follow-up work to clarify temporal dynamics and long-term integration of psychedelic experiences.

In conclusion, analyses of over 1,200 attendees across six multiday events indicate that recent psychedelic substance use in naturalistic settings is associated with self-reported personal transformation, altered moral values, increased social connectedness and a more positive mood. These associations held after controlling for other substance use, a range of demographic covariates and participants' willingness to consume psychedelics. The authors suggest these field findings corroborate and extend laboratory evidence of psychedelics' mood-enhancing effects and note potential relevance for future investigations of their therapeutic applications.