State of the Science: Ayahuasca 2026

By David Romero

For generations, ayahuasca has been used by Indigenous peoples of the Amazon within traditional healing and spiritual practices. Only relatively recently has Western science begun studying what happens when this ancient medicine is examined through the lenses of psychiatry, neuroscience, trauma, and behavioral health. For Veterans and First Responders, that research is especially interesting because many of the areas being studied — PTSD, depression, substance use, sleep, suicidality, and difficulty reintegrating into everyday life — are challenges that disproportionately affect these communities.

As of 2026, the research is encouraging, but it is important to understand where the evidence actually stands. Ayahuasca is not an established treatment for PTSD, TBI, addiction, or depression, and the science does not support describing it as a cure. What has changed is that there is now enough legitimate research that the conversation has moved beyond anecdotes. Researchers are beginning to ask not only whether people feel better after ayahuasca, but how long those changes last, what might be happening in the brain, and how much preparation, environment, community, and integration contribute to the outcome.

One of the most important studies came from Brazil, where researchers conducted a randomized, double-blind, placebo-controlled trial involving people with treatment-resistant depression. After a single ayahuasca session, participants experienced rapid reductions in depression. Seven days later, 64% of those receiving ayahuasca met criteria for a clinical response compared with 27% receiving placebo. The study was small — only 29 participants — but it remains one of the strongest pieces of controlled evidence supporting ayahuasca’s potential antidepressant effects.^[1]

More recently, researchers have begun looking specifically at Veterans. A 2024 study followed eight military combat Veterans through a brief ayahuasca intervention. Seven demonstrated reliable or clinically meaningful improvements in post-traumatic stress symptoms immediately afterward, with improvements persisting in five of the seven Veterans available at three-month follow-up. Veterans also described greater acceptance, positive emotion, perspective, and renewed purpose. The study was very small and later required a correction regarding the calculation of baseline PTSD scores, so these findings should be considered preliminary, but the research opened an important door.^[2]

That door opened further in 2025 when researchers followed 58 Veterans participating in psychedelic retreats involving either ayahuasca or psilocybin. Rather than focusing exclusively on PTSD, they examined depression, anxiety, sleep, quality of life, mental well-being, post-concussive symptoms, and military-to-civilian reintegration. Significant improvements were reported across multiple areas. Because this was a naturalistic study rather than a randomized clinical trial, we cannot say the psychedelics alone caused those improvements, but the findings are particularly relevant to Veterans because trauma rarely exists as one isolated diagnosis.^[3]

This leads to one of the more fascinating questions emerging from psychedelic research: How much of the outcome comes from the medicine itself, and how much comes from everything surrounding it?

A 2021 placebo-controlled study conducted during ayahuasca retreats found that depression, anxiety, and stress improved in both participants receiving ayahuasca and those receiving placebo. Ayahuasca produced some substance-specific effects, but the study demonstrated that expectation, environment, ceremony, social connection, and other aspects of the retreat experience may contribute meaningfully to psychological improvement.^[4]

Rather than weakening the case for psychedelic therapy, this may help us understand it more accurately. The therapeutic process may involve the interaction between the medicine and the environment in which it is experienced. Screening, preparation, trust, skilled support, community, meaning-making, and integration afterward may all influence whether a powerful experience eventually becomes meaningful change.

Other areas of research are beginning to show similarly interesting signals. A 2026 systematic review found preliminary evidence that ayahuasca may be associated with reductions in suicidal ideation, particularly among people experiencing depression, although researchers emphasized that much larger and more focused studies are needed before ayahuasca could be considered a suicide-prevention intervention.^[5] Research into alcohol and substance use has also produced encouraging findings, with observational studies reporting reductions in problematic alcohol and other substance use following ayahuasca experiences. A 2024 review concluded that the evidence surrounding ayahuasca and alcohol-use disorder is promising enough to justify further clinical research.^[6]

There is also considerable interest in what psychedelics may be doing biologically. Preclinical research suggests psychedelics can influence processes involved in neuroplasticity — the brain’s ability to reorganize and form new patterns of connection. Researchers have investigated pathways involving serotonin signaling, synaptic remodeling, dendritic growth, and brain-derived neurotrophic factor, or BDNF. Human ayahuasca studies have found associations between BDNF and antidepressant response, but the evidence remains mixed, and a 2024 meta-analysis did not find reliable increases in peripheral BDNF across psychedelic studies overall.

This distinction becomes especially important when discussing traumatic brain injury. The 2025 Veteran retreat study reported improvements in self-reported post-concussive symptoms, but that does not mean ayahuasca has been shown to repair TBI. PTSD, poor sleep, depression, anxiety, headaches, cognitive fatigue, and concussion symptoms overlap considerably. A Veteran may experience meaningful improvements in functioning without damaged brain tissue literally regenerating. Neuroplasticity research is exciting, but claims that ayahuasca “repairs the brain” currently move well beyond what human evidence supports.

Safety also has to remain central to this conversation. Ayahuasca contains DMT along with beta-carboline compounds that inhibit monoamine oxidase, which makes medication screening particularly important. Cardiovascular conditions, psychiatric instability, vulnerability to mania or psychosis, and certain medication combinations can increase risk. Modern reviews generally suggest that ayahuasca can be reasonably tolerated in appropriately screened populations and controlled settings, but “natural” should never be confused with universally safe.

Looking forward, some of the most valuable research may come from studying Veterans beyond traditional symptom scores. PTSD scales matter, but so do sleep, alcohol use, anger, relationships, employment, physical health, parenting, purpose, community connection, and the ability to transition from military or First Responder identity into the next chapter of life. Combining these measures with tools such as EEG, functional MRI, cognitive testing, autonomic measurements, and longer follow-up periods may eventually help researchers understand not only whether someone improves, but why.

Perhaps that is where the ayahuasca research becomes most interesting. Psychedelic medicine is challenging the traditional idea that treatment always consists of giving someone a compound and measuring whether a symptom decreases. A psychedelic experience may instead create a temporary period in which emotions, memories, beliefs, and behavioral patterns become more flexible. What happens during that window — and especially what someone does afterward — may ultimately determine how much of the experience translates into everyday life.

For Veterans and First Responders, that means the future of psychedelic medicine may involve far more than the ceremony itself. Preparation, responsible screening, skilled facilitation, therapy when appropriate, movement, sleep, nutrition, family support, community, spiritual practice, and meaningful integration may all become parts of a larger therapeutic model.

The state of the science in 2026 therefore calls for both optimism and patience. We now have controlled evidence supporting rapid antidepressant effects, emerging Veteran research showing improvements across several areas of psychological functioning, preliminary findings involving suicidality and substance use, and an expanding body of neuroscience exploring how psychedelics may create periods of increased psychological flexibility. At the same time, much of the ayahuasca literature remains small, observational, or preliminary.

The goal should not be to prove that ayahuasca is a miracle medicine. It should be to understand where it helps, where it does not, who may benefit, who may be at greater risk, and what conditions create the safest opportunity for lasting change.

For Veterans and First Responders considering this emerging field, perhaps the most useful question is no longer simply, “Does ayahuasca work?” The better question is becoming: For whom, under what circumstances, with what preparation and support, and does the person’s life meaningfully improve afterward?

Science is finally beginning to give us some answers.

This article is intended for education and harm reduction and should not be interpreted as medical advice or as an endorsement of psychedelic use. Ayahuasca remains federally illegal in the United States outside limited legally protected religious contexts, and individuals considering psychedelic medicines should carefully evaluate medical, psychiatric, medication, and legal risks.

Sources

1. Palhano-Fontes et al., Psychological Medicine — Rapid antidepressant effects of ayahuasca in treatment-resistant depression ↩
2. Weiss et al., mixed-methods case series — Ayahuasca in the treatment of PTSD in military combat veterans ↩
3. Calnan et al., Brain and Behavior — Psychedelics administered to military veterans in naturalistic retreat settings ↩
4. Uthaug et al., Psychopharmacology — A placebo-controlled study of ayahuasca, set and setting ↩
5. Zeifman et al., Frontiers in Pharmacology — The impact of ayahuasca on suicidality ↩
6. Bouso et al., Drug and Alcohol Review — Ayahuasca consumption and alcohol/drug use ↩

Keep reading

• A study of 58 veterans in psychedelic retreats
• The Rythmia and CHP veteran retreat week
• More research summaries

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