Scientific Studies and Outcomes

Recent (and relatively recent) scientific research studies on the use of ayahuasca in treating anxiety and depression

 

Randomized Controlled Trial (Treatment-Resistant Depression)

Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression — In a double-blind, placebo-controlled trial (N=29), a single dose of ayahuasca produced significant reductions in depression scores (Montgomery-Åsberg Depression Rating Scale) compared to placebo, up to 7 days post-dose. PubMed

Effect sizes were large (Cohen’s d = 1.49 at day 7), suggesting a strong antidepressant effect. PubMed

 

Long-Term Observational Study (Depressed Patients)

Therapeutic effect of an ayahuasca analogue in clinically depressed patients — In 20 clinically depressed participants, Beck’s Depression Inventory (BDI) scores dropped substantially after a ceremony and remained lower at 1 month and 1 year follow-up. PubMed+1

The study also found increases in mindfulness and life satisfaction correlated with the improvements. SpringerLink+1

 

Naturalistic Retreat Study

Ceremonial Ayahuasca in Amazonian Retreats — This six-month naturalistic study found that participants reported sustained reductions in depression, anxiety, and global psychological distress after attending ayahuasca retreats. Frontiers

They also found epigenetic changes (changes in DNA methylation) in the SIGMAR1 gene, suggesting possible underlying biological mechanisms. Frontiers

 

Long-Term Psychological Health in Specific Populations

Long-term benefits to psychological health and well-being after ceremonial use of ayahuasca in immigrants and refugees — In a sample of Middle Eastern and North African (MENA) immigrants/refugees, ceremonial use of ayahuasca was associated with significant reductions in depression and anxiety, and improvements in self-compassion and cognitive reappraisal. PubMed

The same study noted that most participants reported no lasting adverse effects, and positive behavioral changes persisted for months. Frontiers+1

Cross-Sectional Survey (Very Large Sample)

 

Ayahuasca use and reported effects on depression and anxiety symptoms:

An international cross-sectional study of 11,912 consumers — Among those who reported depression or anxiety, 78% said their depression was “very much” or “completely” improved after using ayahuasca; 70% reported similar improvements for anxiety. researchers.westernsydney.edu.au

However, the authors also note that this is self-reported data (cross-sectional), so it has limitations in establishing causality. researchers.westernsydney.edu.au

 

Mechanistic / Psychological Insights

Ayahuasca’s Antidepressant Effects Covary with Behavioral Activation as Well as Mindfulness — In a study of 152 people, reductions in depressive symptoms after ayahuasca correlated strongly with increased mindfulness (and, moderately, with behavioral activation). PubMed

This suggests that part of how ayahuasca helps may be by boosting psychological processes like present-moment awareness and active engagement in life.

 

Review / Integrative Analyses

Therapeutic efficacy of ayahuasca in patients with mental disorders: an integrative review — This review summed up clinical studies (2015–2021) and found rapid and sustained antidepressant effects, even in people with suicidal thoughts. RSD Journal

 

Therapeutic use of ayahuasca: a review of the evidence … in depressive disorders

Another review in European Psychiatry concluded that ayahuasca use is associated with reductions on depression scales, improvements in mood, self-acceptance, emotional processing, etc. Cambridge University Press & Assessment

Evidence on the antidepressant effects of Ayahuasca: an integrative review — Reviews studies from 2016–2022 confirming that the antidepressant effects are consistent and promising. RSD Journal

 

Community-Based Mental Health Program (Yaqui Indigenous Population, Mexico)

Preliminary results from a community-based ayahuasca-assisted mental health program among a Yaqui Indigenous population — Journal of Psychedelic Studies, 2024.

In 37 patients (depression, anxiety, grief, substance use), after two ayahuasca ceremonies with psychotherapeutic support: BDI-II (depression) dropped from ~15.7 to 5.1, BAI (anxiety) from ~16.6 to 6.3. akjournals.com

Authors report the ceremonies were well tolerated. akjournals.com

 

Long-Term Psychological Health in Refugees / Immigrants

Long-term benefits to psychological health and well-being after ceremonial use of Ayahuasca in Middle Eastern and North African (MENA) immigrants/refugees. Frontiers in Psychiatry, 2024. Frontiers

Findings: significant reductions in depression, anxiety, and shame; increases in self-compassion and cognitive reappraisal. PubMed+1

Most participants reported no lasting adverse effects; behavioral improvements persisted months later. Frontiers

 

Naturalistic Longitudinal Study (Personality, Mood, Well-Being)

Changes in mental health, wellbeing and personality following ayahuasca consumption: Results of a naturalistic longitudinal study. (Published; data from 2023-ish) PubMed

Sample: 53 retreat participants assessed before and 1-month after ayahuasca.

Results: Large reductions in depression, anxiety, and stress, along with increases in positive mood, self-efficacy, spiritual openness, and satisfaction with relationships. PubMed

Predictors: those with higher negative emotionality and low self-efficacy at baseline saw larger mental health improvements. PubMed

 

Systematic Review (Up to 2022, but influential for recent context)

A Systematic Review on the Therapeutic Effects of Ayahuasca. Published 2023 in PubMed. PubMed

The review included 66 peer-reviewed studies and found consistent evidence that ayahuasca may benefit depression and anxiety, plus other psychological conditions. PubMed

Also discussed biological mechanisms (inflammation, neuroplasticity, etc.) that could explain therapeutic effects. PubMed

 

Longitudinal Clinical Study in Depressed Patients

Therapeutic effect of an ayahuasca analogue in clinically depressed patients: a longitudinal observational study. (Psychopharmacology, originally published 2022, but follow-up data is very relevant in 2024–2025) SpringerLink+1

In 20 clinically depressed individuals, after one ayahuasca ceremony: BDI (depression) scores dropped significantly at 1-day, 1-month, and even 1-year follow-up. PubMed+2PMC+2

At 1 year, ~71% of participants were in remission (BDI < 13). PMC+1

Also observed were increases in mindfulness and life satisfaction, and reductions in anxiety/stress measures. SpringerLink

 

Risk, Mediating Factors & Mental Health

Ayahuasca’s Mediating Role in Mental Health — ICEERS summary of a recent (2025) PLOS Mental Health re-analysis of the Global Ayahuasca Survey. ICEERS>

Key findings: people with a history of anxiety or depression reported more adverse mental states after ayahuasca; but higher frequency of use and more intense “visual distortions” during sessions were associated with better long-term mental health (measured via SF-12). ICEERS>

Suggests that both pharmacological effects and set-and-setting (the psychological experience) mediate mental health outcomes. ICEERS>

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Caveats & Important Notes

Setting matters: Many of the positive outcomes come from ceremonial or retreat settings (i.e., not just pharmacological). The “set and setting” (mindset + environment) play a big role. PubMed

Risk / safety: While many studies report positive effects, ayahuasca is not risk-free. The reviews call for more large-scale, controlled studies to better establish safety and long-term effects. Cambridge University Press & Assessment

Self-report bias: The cross-sectional survey (11,912 users) is based on self-report, so there may be selection bias: people who felt better may have been more likely to respond. researchers.westernsydney.edu.au

Not yet mainstream therapy: Despite promising evidence, ayahuasca is not (yet) a standard clinical treatment for depression or anxiety, and legal/ethical issues remain in many places.

 

 

Recent (and relatively recent) scientific research studies on the use of ayahuasca in treating drug addiction / substance use disorders:

 

Ayahuasca Treatment Outcome Project (ATOP): One-Year Results

One-year follow-up of 52 participants in the Takiwasi Centre (a Peruvian therapeutic community) after ayahuasca-assisted integrative treatment. Results showed significant reductions in drug and alcohol severity, anxiety, depression, and improvements in quality of life. PubMed

Within-treatment changes in a novel addiction treatment program using traditional Amazonian medicine

 

Study of the Takiwasi treatment program: measured addiction severity and neuropsychological functioning from intake to 2+ months into treatment. Found early and sustained positive changes, suggesting treatment safety and therapeutic benefit. PubMed

Pilot Evaluation of a Residential Drug Addiction Treatment Combining Traditional Amazonian Medicine, Ayahuasca and Psychotherapy

 

Inpatient addiction treatment combining ayahuasca rituals + psychotherapy (N = 31). Significant reductions in anxiety and depression, and increases in quality of life and spirituality at discharge. PubMed

Associations between ayahuasca consumption in naturalistic settings and current alcohol and drug use

Large cross-sectional survey (8,629 participants across ~40 countries) showing that more frequent ayahuasca use is strongly associated with lower self-reported alcohol consumption and use of other drugs, especially among those with prior substance use disorder. PubMed

 

Effects of ayahuasca and its alkaloids on substance use disorders: a systematic review (2016–2020)

Review of preclinical (animal) and human observational studies. Reports therapeutic effects (reduced drug use, increased well-being), but highlights limitations (lack of RCTs, dose-standardization issues). PubMed

Exploring Changes in Substance Use Patterns Pre- and Post-Ayahuasca Retreats

Longitudinal study (SSWR 2024) of 117 retreat participants (Costa Rica / Peru). Reported significant reductions at one-month follow-up in use frequency and craving for substances including alcohol, cannabis, stimulants, and tobacco. sswr.confex.com

 

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