Skip to content

May 2026

Altered states of consciousness

What May 2026's 11 new studies found, synthesized from the papers below. All Altered states of consciousness research →

The synthesis

Synthesized from 6 studies in the library · AI-generated, grounded in the abstracts below

Found by searching the library for Altered states of consciousness, non-ordinary states, altered consciousness, ASC, then ranked by relevance.

Research in May 2026 on altered states of consciousness, particularly ayahuasca, shows preliminary evidence of changes in brain topology (persistent entropy) and potential therapeutic benefits for suicidality and Parkinson's disease, but findings are limited by small samples, lack of controls, and mixed results regarding cumulative effects on ego dissolution compared to meditation. A case report also highlights serious risks of serotonin syndrome when ayahuasca is combined with other serotonergic drugs. Overall, the evidence is insufficient to draw firm conclusions due to small sample sizes, exploratory designs, and inconsistent findings.

Confidence in the evidence

Insufficient
  • Only one fMRI study with nine participants and no placebo control showed a nominal effect that did not survive correction.
  • Qualitative study on suicidality had nine participants and no control group, limiting generalizability.
  • Preclinical study on Parkinson's disease used animal models, not human subjects.
  • Longitudinal study on resilience and acute effects had a moderate sample (n=233) but was observational and exploratory.
  • Comparative study on ego dissolution found no cumulative effect of ayahuasca, contrasting with meditation, but relied on self-report measures.
  • Case report of serotonin syndrome is a single incident, not systematic evidence.
How we rate confidence

Confidence reflects the strength of the underlying evidence, not whether the result is favorable. It weighs the number and size of studies, their design (randomized trials count for more than observational or single-case work), how consistently they point the same way, and their risk of bias.

Tiers run from Insufficient to High. High is rare in this field: small, early, or open-label studies land lower even when their direction is encouraging.

Evidence by study

Direction is each study's finding relative to your question: Supports, Opposes, No effect, Mixed, or Unclear.

An exploratory persistent-homology analysis of resting-state fMRI functional connectivity under Ayahuasca 2026
Mixed

Persistent entropy of H2 features showed a nominal pre/post decrease that did not survive correction and was not reproduced in a secondary analysis.

observational Sample size: 9

Ayahuasca use and improvements in suicidal behavior: An exploratory qualitative study 2026
Supports

Ceremonial ayahuasca use was perceived to reduce suicidal ideation and behavior, with three thematic categories identified.

qualitative Sample size: 9

Therapeutic properties of ayahuasca component N,N-Dimethyltryptamine in a pre-clinical model of Parkinson's disease 2026
Supports

DMT administration resulted in molecular changes consistent with reduced neuroinflammation and neuronal preservation, and behavioral improvements.

preclinical

Baseline Resilience as a Predictor of Ayahuasca Acute Effects and Moderator of the Relationship between Acute Effects and Psychospiritual Outcomes 2026
Mixed

Higher baseline resilience predicted more intense acute challenging experiences, but the relationship between acute effects and psychospiritual outcomes was exploratory.

observational Sample size: 233

Investigating Hypo‐Egoic Features: Ayahuasca's Psychedelic Path Versus Meditation's Mindful Journey 2026
Mixed

Meditators had higher ego dissolution scores than ayahuasca users, and repeated ayahuasca exposure showed no cumulative association with ego dissolution.

observational Sample size: 174

B48-13 Severe Serotonin Syndrome With Acute Respiratory Failure Following Ayahuasca and Dextromethorphan Use: A Case Report 2026
Opposes

Severe serotonin syndrome with acute respiratory failure occurred after combining ayahuasca with dextromethorphan, requiring intubation and ICU care.

case report Sample size: 1

Points of agreement

  • Ayahuasca shows potential for therapeutic effects in neuropsychiatric conditions (suicidality, Parkinson's disease) and alters brain connectivity.
  • Acute effects of ayahuasca can be both challenging and beneficial, with individual factors like resilience playing a role.
  • There is a risk of serotonin syndrome when ayahuasca is combined with other serotonergic agents.

Conflicts

  • One study found a nominal decrease in persistent entropy (brain topology) after ayahuasca, but another analysis did not replicate this.
  • Meditation showed a cumulative effect on ego dissolution, while ayahuasca did not, suggesting different mechanisms for ego modulation.
  • Higher resilience predicted more intense challenging experiences, which contrasts with the expectation that resilience would buffer negative effects.

Gaps

  • Lack of placebo-controlled, randomized trials for ayahuasca effects on brain function and clinical outcomes.
  • Small sample sizes in most studies (n=9, n=37) limit generalizability.
  • No long-term follow-up data on durability of therapeutic effects or risks.
  • Limited diversity in study populations (mostly White, North American, or Brazilian).
  • No studies on dose-response relationships or standardized dosing protocols.
  • Absence of studies comparing different ceremonial contexts or routes of administration.
Browse these studies in the library