April 2026
Altered states of consciousness
What April 2026's 10 new studies found, synthesized from the papers below. All Altered states of consciousness research →
The synthesis
Synthesized from 2 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 April 2026 found that ayahuasca consistently reduces suicidal ideation and depressive symptoms in treatment-resistant depression, with effects linked to neuroplasticity and default mode network modulation. A large longitudinal study showed lasting improvements in personality, quality of life, and decentering among Western participants in Shipibo-led retreats, with minimal adverse effects. However, evidence is limited by small sample sizes, methodological heterogeneity, and lack of large-scale controlled trials.
Confidence in the evidence
Low-Moderate- Only two relevant studies directly address the question: a systematic review (5 studies) and a prospective longitudinal study (n=264).
- The systematic review highlights methodological heterogeneity and calls for larger, rigorous trials.
- The longitudinal study is open-label and lacks a control group, limiting causal inference.
- Other studies are off-topic (legal, cardiovascular, machine learning, zebrafish, theoretical reviews).
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.
| Study | Design | Sample size | Direction | Finding |
|---|---|---|---|---|
| Ayahuasca Therapy: Possible Reduction of Suicidal Ideation in Treatment-Resistant Depression - A Systematic Review. 2026 | systematic review | 5 | Supports | Ayahuasca administration is consistently associated with rapid and significant reductions in suicidal ideation and depressive symptoms in treatment-resistant depression. |
| Symmetrical Global Mental Health (Sym-GMH): Ayahuasca and shipibo traditional medicine for lasting changes in personality and quality of life 2026 | prospective longitudinal study | 264 | Supports | Over 12 months, participants showed significant reductions in Neuroticism, improvements in quality of life and decentering, with 91.7% reporting long-term benefits and minimal adverse effects (2.3%). |
Ayahuasca administration is consistently associated with rapid and significant reductions in suicidal ideation and depressive symptoms in treatment-resistant depression.
systematic review Sample size: 5
Over 12 months, participants showed significant reductions in Neuroticism, improvements in quality of life and decentering, with 91.7% reporting long-term benefits and minimal adverse effects (2.3%).
prospective longitudinal study Sample size: 264
Points of agreement
- Both studies report positive effects of ayahuasca on mental health outcomes, including reduced depressive symptoms and improved well-being.
- Both highlight the role of neuroplasticity and default mode network modulation as underlying mechanisms.
Conflicts
- No direct conflicts; the systematic review notes methodological heterogeneity across included studies, but findings are consistent.
Gaps
- Lack of large-scale, randomized controlled trials with active placebos.
- Durability of effects beyond 12 months is not assessed.
- Limited diversity in populations (mostly Western participants in retreat settings).
- No studies on dose-response or long-term safety in clinical populations.