Veterans who attended psilocybin or ayahuasca retreats reported improvements across PTSD, depression, and other measures about four weeks later.
A 2025 study followed veterans who attended psilocybin or ayahuasca retreats, measuring their mental health before and after.
This naturalistic study surveyed 58 veterans before and after they attended psilocybin or ayahuasca retreats, using eight mental-health questionnaires up to four weeks each side. All eight measures improved, with the biggest changes in depression (about 29% lower) and PTSD (about 26% lower). Psilocybin retreats showed greater improvement on most measures, while ayahuasca edged ahead on PTSD. Because veterans chose to attend and there was no comparison group, the design can't separate the psychedelics' effects from expectation, the retreat setting, and self-selection.
This naturalistic pre-post study surveyed 58 military veterans who self-selected to attend psilocybin or ayahuasca retreats, using eight self-report questionnaires (including PCL-5 and PHQ-9) up to four weeks before and after. All eight outcomes improved significantly, with the greatest improvements in depression (PHQ-9, 29.1%) and PTSD (PCL-5, 26.1%). Psilocybin retreats showed greater improvement on seven of eight outcomes; ayahuasca showed a slightly greater PTSD improvement.
As a naturalistic, uncontrolled, self-report study of self-selected retreat attendees, it cannot separate any psychedelic effect from placebo, expectancy, the communal retreat context, or regression to the mean — attendees with worse baseline scores improved most, consistent with regression. It is hypothesis-generating about real-world retreat settings, not evidence of efficacy.
It joins a growing set of naturalistic reports of psychedelic retreats in veterans, and should be read against controlled trials that have tempered hopes — for example, smoked cannabis and repeated ketamine infusions that did not beat placebo for PTSD (Bonn-Miller et al., 2021; Abdallah et al., 2022).
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