Psilocybin-assisted therapy reduced PTSD symptoms in a pilot study of military veterans.
Psilocybin-assisted therapy reduced PTSD symptoms in a pilot study of military veterans.
Post-traumatic stress disorder (PTSD) can remain severe even after sustained medication and psychotherapy. A pilot study examined safety and early symptom changes during a course of psilocybin-assisted therapy in US military veterans whose symptoms had resisted those treatments.
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Twelve carefully screened veterans completed the trial, which had no control group and was not blinded. After eight hours of preparatory therapy, participants received two supervised doses of synthetic psilocybin, 15 and 25 milligrams, two to three weeks apart, with follow-up therapy after each session. Safety was the main focus of the study. However, an independent clinician also assessed PTSD severity through a structured interview scored from 0 to 80, with higher scores indicating worse symptoms.
- At one month after the second dose, 9 of 12 participants met remission criteria with clinician-rated symptom scores at least 50% below baseline. The average score dropped from 39.7 to 12.2 across the treatment course.
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Veterans who improved more during preparation tended to show greater clinician-rated PTSD symptom improvement.
- On average, participants' own symptom ratings also remained well below baseline one week and one month after the second dose.
- All reported study-related adverse effects were mild to moderate and temporary, with no serious adverse events reported. Headache, anxiety, and dizziness were the most common effects.
- The study did not find a clear reduction in the intensity of suicidal thoughts.
Building trust with the therapists may have helped participants feel safe enough to approach difficult emotions rather than avoid them. That sense of safety, combined with encouragement to respond with curiosity and acceptance, could make challenging experiences during the psilocybin sessions easier to explore. Follow-up therapy then offered a way to make sense of those experiences and consider different responses to trauma-related thoughts and feelings. The continuing therapeutic relationship may therefore have helped translate what happened during the psilocybin sessions into changes in everyday life.
The two psilocybin doses were only one part of the treatment. The full approach also involved preparation and follow-up therapy, requiring more time and professional support than just taking psilocybin.