Effects of Ayahuasca on Gratitude and Relationships with Nature: A Prospective, Naturalistic Study

This was a prospective, naturalistic, open-label within-subjects study conducted at Soltara Healing Centre, an ayahuasca retreat in Costa Rica where participants received ceremonies led by indigenous Shipibo curanderos. Recruitment occurred via the retreat's website and email after retreat registration; participation required informed consent and Institutional Review Board approval. All retreat attendees meeting the centre's entry criteria (age ≥18, no contraindicated psychiatric disorders, medications, or medical conditions) were eligible. Participants were entered into a prize drawing as compensation. Participants stayed 5–12 nights and attended between 2 and 7 ayahuasca ceremonies (mean 3.67, SD 0.85). Surveys were administered online via Qualtrics at three timepoints: T1 (one week before retreat, baseline), T2 (one week after retreat), and T3 (one month after retreat). At T1 participants provided demographics and completed the Appreciation Scale (AS), the Nature Relatedness 6-item scale (NR-6), and the Appreciation of Nature (APR) scale. At T2 they completed the same measures plus the Mystical Experience Questionnaire (MEQ30), the Awe Experience Scale (AWE-S), and the Ego Dissolution Inventory (EDI), each answered with reference to the participant's most intense ayahuasca session. T3 repeated the baseline measures (except demographics). Analyses focused on within-subject change across time. The AS facets were analysed using a 3 × 8 repeated-measures analysis of variance (ANOVA) with Time (T1, T2, T3) and eight AS facets; planned pairwise comparisons tested temporal differences. NR-6 and APR total scores were each tested with one-way repeated-measures ANOVAs across the three timepoints. One-week and one-month change scores (∆1 = T2–T1; ∆2 = T3–T1) were computed for AS, NR-6, and APR. Two-way Pearson correlations assessed relationships between acute subjective measures (MEQ30, AWE-S, EDI) and change scores, and the number of ceremonies was correlated with changes to test dose/quantity effects. Baseline predictors (age, prior psychedelic use) were evaluated via Pearson correlations with acute measures.

Participant flow began with 77 completing baseline; 65 completed T2 and 55 completed T3. One person who did not partake in ceremonies was excluded, yielding a final analytic sample of N = 54 (mean age 41.17, SD 11.24; 24 female). The sample was predominantly highly educated (88.9% college degree or higher), majority non-Hispanic white (74.1%), and had varied prior psychedelic experience (18.5% reporting never having used psychedelics). Participants attended an average of 3–4 ceremonies during their stay. Gratitude: The AS total exhibited a significant main effect of Time (F(1,53) = 34.97, p < .001, eta_p^2 = 0.40). Planned comparisons showed AS total scores at one week (T2) and one month (T3) post-retreat were each significantly higher than baseline (T1), while T2 and T3 did not differ from one another. All eight AS facets increased at both follow-ups versus baseline, and the Time × Facet interaction was significant (F(1,53) = 5.68, p < .001, eta_p^2 = 0.10), with the ritual and interpersonal facets showing significant differences at T2 and T3 but not at baseline. Correlations between change in gratitude and the number of ceremonies were negligible and non-significant (one-week r = .04, p = .80; one-month r = −.05, p = .70). Scores on the AWE-S and MEQ30—but not the EDI—were weakly to moderately correlated with one-week and one-month changes in AS total scores. Nature relatedness and appreciation: For the NR-6, Time had a significant effect (F(1,53) = 26.27, p < .001, eta_p^2 = 0.33); NR-6 scores at T2 and T3 were higher than baseline and did not differ from each other. The APR likewise increased over time (F(1,53) = 31.79, p < .001, eta_p^2 = 0.38) with T2 and T3 both exceeding T1 and no difference between follow-ups. Changes in NR-6 and APR were weakly correlated with AWE-S and MEQ30 scores, but not with EDI. Mystical-type experiences and baseline predictors: Applying a 60% threshold on MEQ30 subscales to define a "complete mystical-type experience," 37 of 54 participants (68.52%) met this criterion. Age was negatively correlated with acute intensity as measured by MEQ30 (r = −.34, p = .010) and AWE-S (r = −.39, p = .004), but not significantly correlated with EDI (r = −.18, p = .140). Prior lifetime psychedelic use did not correlate significantly with MEQ30 (r = .11, p = .424), AWE-S (r = .05, p = .703), or EDI (r = .11, p = .388).

The investigators interpret the results as evidence that participation in ayahuasca ceremonies within a retreat setting was followed by sustained increases in self-reported gratitude, nature relatedness, and nature appreciation at one week and one month post-retreat. Acute mystical-type experiences and feelings of awe during the most intense ayahuasca session were weakly to moderately associated with these post-acute increases, whereas ego dissolution was not, suggesting that specific facets of the acute subjective experience may be more relevant to prosocial change than others. Authors situate these findings alongside prior work with psilocybin and observational studies of other psychedelics, noting similar links between mystical-type experiences/awe and increases in gratitude or nature relatedness. They propose a plausible mechanism in which awe-evoking experiences create meaningful memories that increase gratitude and buffer emotional distress, though they stop short of causal claims given the observational design. The discussion acknowledges that some observed changes may reflect non-pharmacological aspects of the retreat (for example, natural surroundings, activities such as yoga or hiking, and social interactions), but also points out that related pro-environmental and gratitude effects have been reported in laboratory studies of synthetically manufactured psychedelics, supporting the likelihood of at least a partial pharmacological contribution. Key limitations acknowledged by the authors include the open-label, uncontrolled design without a blinded placebo condition, the confounding influence of the retreat context, reliance on self-report measures, and a demographically homogenous sample that limits generalisability. They note ongoing debates about feasibility of double-blind placebo control in psychedelic research and suggest naturalistic mechanistic studies as complementary. The authors recommend future research incorporating behavioural and observer-rated measures, longer follow-up intervals to characterise durability of effects, more diverse samples to test potential moderators (including race), and examination of whether prosocial changes mediate clinical improvements. Strengths highlighted include good participant retention, multiple post-acute follow-ups, ecological validity, use of validated multi-faceted measures, and identification of acute-state correlates of post-acute change. The authors conclude that their results support anecdotal reports that ayahuasca-induced mystical experiences and awe are linked with sustained increases in gratitude and relationships with nature, and that these changes could have implications for mental health and broader societal outcomes, while emphasising the need for randomized controlled trials to address the study's limitations.