Ayahuasca in the treatment of posttraumatic stress disorder: Mixed-methods case series evaluation in military combat veterans.
Brandon Weiss, Lê-Anh Dinh-Williams, Nick Beller, Ian M Raugh, Gregory P Strauss, William K Campbell
Psychological Trauma: Theory, Research, Practice and Policy December 1, 2024 DOI: 10.1037/tra0001625 (opens in new tab)
The journal has published a correction to this paper. Read the correction (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Convergent mixed-methods case series Qualitative Case report Peer reviewed |
|---|---|
| Sample size | 8 |
| Population | Military veterans with PTSD symptoms |
| Intervention | Ayahuasca |
| Duration | 3-day intervention, 3-month follow-up |
| Topics | Ayahuasca PTSD |
| Keywords | PTSD-Treatment Psychedelic-therapy Veterans-health Trauma-recovery Ayahuasca-research |
| Citations | 16 |
| Key findings | The majority of veterans showed reliable or clinically significant improvements in PTSD symptoms after the ayahuasca intervention, with most improvements maintained at three months. |
Abstract
[Correction Notice: An Erratum for this article was reported online in Psychological Trauma: Theory, Research, Practice, and Policy on Jul 25 2024 (see record 2025-07042-001). In the original article, there was an error in the calculations that led to the overstatement of the symptom severity of the veteran sample. Specifically, sum scores for the posttraumatic stress disorder (PTSD) symptom checklist (PCL-5) were scored using a 1-5 Likert scale rather than the appropriate 0-4 Likert scale. As a result, although it was stated that participants in the veteran sample exhibited clinical levels of PTSD based on the >33 PCL-5 threshold associated with a PTSD diagnosis, the levels actually reflected moderate posttraumatic stress symptoms. In addition, estimates of significantly reliable change in PCL-5 scores after an ayahuasca intervention (from 87.5% to 71.4%) were modified, and the threshold criteria for clinically significant changes (posttreatment scores <28) were removed because several participants met these criteria at baseline, thus impacting the interpretation of treatment outcomes.] Objective: Although ayahuasca-a plant-based psychedelic-is discussed as promising in the treatment of posttraumatic stress disorder (PTSD), evidence so far remains limited to retrospective case reports and qualitative surveys. No study to date has examined whether ayahuasca results in prospective and clinically meaningful changes in trauma symptoms across individuals with PTSD symptoms. To address this gap, we conducted a convergent mixed-methods case series study on eight military veterans with PTSD who participated in a 3-day ayahuasca intervention in Central America. Clinically meaningful changes from pre- to posttreatment and at a 3-month follow-up were assessed in three ways using: (a) PTSD checklist-5 (PCL-5); (b) experience sampling measurement of momentary PTSD and mood symptoms; and (c) an open-ended survey on perceived benefits. The majority (87.5%; 7/8) of participants demonstrated reliable and/or clinically significant changes in PCL-5 symptoms by posttreatment, which were maintained by 70% (5/7) of veterans by the 3-month follow-up. On average, veterans also reported significant improvements in momentary PTSD symptoms, as well as negative and positive affect in daily life posttreatment, with 63% (5/8) reporting moderate-to-large improvements in these domains. Broad themes characterizing the perceived benefits of ayahuasca included deep positive emotions, decentering/acceptance, and purpose in life; adverse acute experiences were, however, reported. This study provides preliminary support for the clinically meaningful and lasting benefits of a brief ayahuasca intervention on PTSD/mood symptoms in military veterans. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
Comparable studies
Other case reports and case series on ayahuasca, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| A fatal intoxication following the ingestion of 5-methoxy-N,N-dimethyltryptamine in an ayahuasca preparation. 25-year-old white male | 2005 | Case study | n = 1 |
| The Diaspora of Brazilian Religions | 2013 | Ethnographic case studies | |
| EEG Gamma Coherence and Other Correlates of Subjective Reports During Ayahuasca Experiences Experienced ayahuasca users | 2005 | Exploratory case series | n = 2 |
| Reply to “Ayahuasca turned on my mind’s eye”: A case of acquired versus congenital aphantasia, as evidenced with DMT use? Individual with apparent congenital aphantasia | 2018 | Case study | n = 1 |
| “Ayahuasca turned on my mind’s eye”: Enhanced visual imagery after ayahuasca intake in a man with “blind imagination” (aphantasia) A man self-diagnosed with long-lasting aphantasia | 2018 | Case study | n = 1 |
Citations in the library
Cited by 17
- Psychedelics: A review of their effects on recalled aversive memories and fear/anxiety expression in rodents Neuroscience & Biobehavioral Reviews September 20, 2024
- How Psychedelics Modulate Multiple Memory Mechanisms in Posttraumatic Stress Disorder. Drugs November 1, 2024
- Acute subjective effects of psychedelics in naturalistic group settings prospectively predict longitudinal improvements in trauma symptoms, trait shame, and connectedness among adults with childhood maltreatment histories. Progress in Neuro-Psychopharmacology and Biological Psychiatry April 2, 2025
- The emotional architecture of the psychedelic brain Trends in Cognitive Sciences August 18, 2025
- Exploring the Therapeutic Effects of Psychedelics Administered to Military Veterans in Naturalistic Retreat Settings Brain and Behavior July 1, 2025
and 12 more in the library