The Shipibo ceremonial use of ayahuasca to promote well-being: an observational study

Longitudinal observational study of 200 Western participants in an Indigenous Shipibo healing program with ayahuasca ceremonies in Peru. Significant improvements in psychological well-being, subjective well-being, spiritual well-being, and quality of life at all time points up to 12-month follow-up (p < 0.01). Effect sizes were large (Cohen's d = 0.82-1.12 for psychological well-being). Decentering correlated with well-being improvement (r = 0.57). Subgroup ANOVA confirmed changes were due to the retreat, not passage of time.