From Egoism to Ecoism: Psychedelics Increase Nature Relatedness in a State-Mediated and Context-Dependent Manner

Kettner and colleagues frame the study within two converging concerns: a growing human disconnection from nature that is linked to poorer mental health and ecological harm, and emerging evidence that classical psychedelics can increase people's sense of connectedness. Earlier work has reported cross-sectional associations between lifetime psychedelic use and higher nature relatedness, and small prospective findings after clinical psilocybin administration, but the causal nature of this relationship and the role of acute experiential factors and environmental context remain unclear. The present study set out to test whether a psychedelic experience leads to increases in nature relatedness in healthy people, and to examine which acute-state factors and contextual variables predict such change. Specifically, the investigators hypothesised that higher lifetime psychedelic use would be associated with greater baseline nature relatedness, that nature relatedness would increase at two and four weeks after a planned psychedelic experience (and correlate with changes in psychological well-being), and that the extent of ego-dissolution and the influence of natural settings during the acute state would predict post-psychedelic increases in nature relatedness.

The researchers conducted a large-scale prospective online survey between March and November 2017, recruiting English-speaking adults who indicated an intention to take a psychedelic in the near future via online advertisements on drug-related websites. Substances included psilocybin (magic mushrooms/truffles), LSD/1P-LSD, ayahuasca, DMT/5-MeO-DMT, Salvia divinorum, mescaline, and iboga/ibogaine. Participants completed questionnaires approximately one week before the planned experience (baseline), one day after, two weeks after, four weeks after, and at a two-year follow-up. The study received favourable ethical review from Imperial College and was coordinated via an online platform; no compensation was provided and the team did not endorse psychedelic use. Key measures at baseline comprised demographics, psychological well-being assessed with the Warwick–Edinburgh Mental Wellbeing Scale (WEMWBS), nature relatedness with the NR-6 short form, and a categorical item on lifetime psychedelic use (Never to >100 times). One day post-experience participants completed measures of acute subjective effects: the Mystical Experience Questionnaire (MEQ), the Ego-Dissolution Inventory (EDI), the Challenging Experience Questionnaire (CEQ), and visual effects (VE) subscales from the Altered States of Consciousness scale. Contextual variables included a binary item on access to nature during the experience and, if affirmative, a visual analogue scale (0–100) rating the perceived influence of nature on the overall quality of the experience. NR-6 and WEMWBS were repeated at two and four weeks; the two-year follow-up included NR-6 and an item on intervening psychedelic experiences. Analyses proceeded in stages. A Spearman correlation tested the association between categorical lifetime psychedelic use and baseline NR-6, with a partial correlation controlling for age. To assess longitudinal change, the investigators used generalized linear mixed models (GLMMs) with gamma regression to accommodate skewed NR-6 distributions, including time as a fixed repeated effect and subject-level random intercepts (and random slopes where appropriate). Post hoc comparisons were performed with Tukey contrasts. Associations between changes in NR-6 and WEMWBS were examined with Pearson correlations. Predictor analyses entered z-standardised EDI, MEQ, CEQ, VE, and perceived influence of nature (VAS) as interactions with time in secondary GLMMs; because EDI and MEQ were highly collinear (r > 0.8), models were run with and without MEQ. A restricted analysis limited to participants with baseline NR-6 at or below the sample mean was also conducted to reduce ceiling effects. Significance was set at p < 0.05 and effect sizes for correlations were interpreted using conventional r thresholds.

Participant retention declined across follow-ups: baseline N = 654, one day N = 379, two weeks N = 315, four weeks N = 212, and two years N = 64. Mean baseline NR-6 was 4.01 (SD = 0.87), higher than comparison values from prior college samples (approximately 3.00–3.34). A moderate positive correlation was observed between lifetime psychedelic use and baseline nature relatedness (Spearman r = 0.306, p < 0.0001); the association remained significant after controlling for age (partial r = 0.267, p < 0.0001). Mean NR-6 values ranged from 3.52 (SD = 1.03) in psychedelic-naïve participants to 4.45 (SD = 0.55) among those reporting >100 lifetime uses. Longitudinal GLMMs indicated a significant main effect of time on NR-6 (β = 0.009, p = 0.014). Tukey post hoc tests showed NR-6 increased from baseline (4.01, SD = 0.87) to two weeks (4.13, SD = 0.81; z = 2.208, p = 0.027) and four weeks (4.12, SD = 0.77; z = 2.253, p = 0.024), with no significant change between the two post‑experience endpoints. Changes in NR-6 correlated positively with changes in well-being: at four weeks the association was moderate (r = 0.331, p < 0.0001) and at two weeks weaker but significant (r = 0.250, p < 0.0001). Predictor analyses (final GLMM across the analysed sample, N = 233) found that ego-dissolution (EDI) significantly interacted with time to predict NR-6 change (β = 0.018, p = 0.014). Including MEQ in the model removed this significance, likely due to collinearity. In the restricted sample with baseline NR-6 ≤ 4.01 (N = 291), the EDI effect grew in magnitude (β = 0.030) but fell to trend level (p = 0.072); perceived influence of access to nature had the largest coefficient in that model (β = 0.032) but also only reached trend significance (p = 0.058). Pearson correlations in the restricted subsample showed a moderate association between the single-item perceived influence of nature and ΔNR-6 (r = 0.361, p = 0.007 among those reporting access to nature) and a weaker association for ego-dissolution (r = 0.203, p = 0.038); MEQ, CEQ, and VE were not significantly correlated with NR-6 change. At approximately two years, time remained a significant predictor in a GLMM including the long-term follow-up (β = 0.013, p < 0.0001). Mean NR-6 was highest at two years (4.38, SD = 0.62) and significantly elevated compared with baseline, two-week and four-week scores. Of the 64 participants completing the two-year follow-up, 47 (73.4%) reported at least one additional psychedelic experience in the interim (median additional experiences = 2). In a limited subset (N = 35) who had both four-week and two-year data, the change between these two timepoints did not correlate with the number of additional psychedelic experiences (r = 0.056, p = 0.748).

Kettner and colleagues interpret their findings as providing the first large-sample prospective evidence that psychedelic experiences can cause increases in nature relatedness in healthy participants. The observed baseline correlation between lifetime psychedelic use and NR-6 is consistent with earlier cross-sectional work, but the prospective increases at two and four weeks – and the elevated scores at two years in the smaller follow-up sample – support a causal effect. The researchers further highlight that increases in nature relatedness tracked improvements in psychological well-being, aligning with prior literature linking nature relatedness to multiple aspects of mental health. Regarding mechanisms, the investigators emphasise the role of acute-state ego-dissolution—defined as a breakdown of self-referential boundaries—in predicting subsequent increases in nature relatedness. They note a strong correlation between ego-dissolution and mystical-type experiences, and suggest that experiences of awe and a diminished sense of self may facilitate an expanded perception of continuity between self and nature. Contextual factors also appear important: in participants with below-average baseline nature relatedness, the perceived influence of natural surroundings during the experience was positively associated with later increases in nature relatedness, pointing to a state-by-context interaction. The authors acknowledge several limitations intrinsic to the web-based observational design. Self-selection bias was likely given recruitment required an intention to use psychedelics, and the sample was highly educated and predominantly male, limiting generalisability. Attrition may have biased long-term findings, and the lack of experimental control meant drug type, dose and purity could not be verified nor were objective measures of the physical setting obtained. They also note reliance on a single-item measure of perceived nature influence and the use of the NR-6 short form, which may have constrained sensitivity and introduced ceiling effects. Kettner and colleagues therefore call for controlled studies that manipulate set and setting, consider validated multi-item measures of nature connection and behaviour, and potentially combine psychedelic administration with nature-based interventions (for example, guided nature contact or inclusion of natural elements in treatment environments). Finally, the authors situate the results within broader public-health and ecological concerns. They argue that, because nature relatedness predicts pro-environmental attitudes and behaviours, psychedelics administered in supportive, nature-enriched contexts could have individual psychological benefits and potentially foster greater environmental awareness. They caution, however, that enhanced environmental concern could also increase distress about ecological degradation and thus underscore the need for safe settings and psychological support during such experiences.

The study concludes that psychedelic use is robustly associated with higher nature relatedness and that a single planned psychedelic experience can prospectively increase nature relatedness in healthy individuals. These post‑experience increases were correlated with improvements in psychological well-being, persisted at a two-year follow-up in the subset assessed, and were predicted by the acute subjective experience of ego-dissolution and, in those with lower baseline nature relatedness, by the perceived influence of natural surroundings. The authors suggest these findings point to the potential for psychedelics, particularly when combined with nature-enriched contexts, to induce enduring positive changes in how people relate to the natural world.