Neurocognitive DisordersNeuroimaging & Brain MeasuresImmunology & InflammationPublic Health, Prevention & Behaviour ChangeAyahuasca

Preliminary evidence of links between ayahuasca use and the corpus callosum

Using MRI data from 22 ayahuasca users and 22 matched controls, the study found preliminary evidence of greater corpus callosum thickness in users—most notably in the isthmus—and a positive association between callosal thickness and number of past ayahuasca sessions in the rostral body, although these effects did not survive corrections for multiple comparisons. These results suggest possible links between ayahuasca use and callosal structure but require replication in larger, ideally longitudinal, samples before clinical conclusions can be drawn.

Authors

  • Jordi Riba
  • Otto Simonsson
  • Draulio Araújo

Published

Frontiers in Psychiatry
individual Study

Abstract

Background

Recent research suggests that ayahuasca and its alkaloid-containing ingredients may be helpful in the treatment and prevention of certain movement and neurodegenerative disorders. However, such research is still in its infancy and more studies in normative samples seem necessary to explore effects of ayahuasca on clinically relevant brain structures, such as the corpus callosum.

Aims

The purpose of the present study was to investigate links between ayahuasca use and callosal structure in a normative sample.

Methods

Using structural imaging data from 22 ayahuasca users and 22 matched controls we compared the thickness of the corpus callosum between both groups at 100 equidistant points across the entire midsagittal surface. In addition, we investigated point-wise correlations between callosal thickness and the number of past ayahuasca sessions.

Results

The corpus callosum was significantly thicker within the isthmus in the ayahuasca group than in the control group. There was also a significant positive correlation between callosal thickness and the number of past ayahuasca sessions within the rostral body, albeit none of these effects survived corrections for multiple comparisons. No region was significantly thicker in the control than in the ayahuasca group, and no callosal region was negatively linked to ayahuasca use, even at uncorrected significance thresholds.

Conclusion

This study provides preliminary evidence of links between ayahuasca use and the corpus callosum. However, future studies need to replicate these findings, preferably using larger sample sizes and ideally also utilizing longitudinal research designs, to draw any practical conclusion and offer implications for follow-up clinical research.

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Research Summary of 'Preliminary evidence of links between ayahuasca use and the corpus callosum'

Introduction

Ayahuasca is a traditional Amazonian botanical brew containing β-carbolines (from Banisteriopsis caapi) and N,N-Dimethyltryptamine (DMT, from Psychotria viridis). When combined, reversible MAO-A inhibitors in the β-carbolines permit orally ingested DMT to reach the central nervous system, producing potent psychoactive effects. Emerging preclinical and clinical work suggests ayahuasca and its alkaloids may influence neurobiological processes relevant to neurodegeneration and motor function, including sigma-1 and serotonin receptor activity, adult neurogenesis, and anti-inflammatory effects. Given these findings and prior links between the corpus callosum and various movement and neurodegenerative disorders, the corpus callosum is a plausible target for investigation in normative samples. De Berardis and colleagues set out to examine whether long-term ayahuasca use is associated with differences in midsagittal corpus callosum thickness. The study compared callosal thickness point-wise across 100 equidistant nodes between 22 ayahuasca users and 22 matched controls, and explored correlations between callosal thickness and the number of past ayahuasca sessions. The authors hypothesised thicker callosal regions in users versus controls and expected effects in the isthmus, a region linked to motor fibres.

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Study Details

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