Study Summary

Fifty healthy participants were randomized to receive a single oral low dose of 1mL/kg of ayahuasca or placebo in this randomized placebo-controlled trial investigating the subacute effects of ayahuasca. Subjective drug effects were assessed using the Hallucinogenic Rating Scale (HRS). Neuroimages were acquired using resting state fMRI and inter- and intra-network functional connectivity analyses were performed using generated salience, visual, sensorimotor, and default mode network maps. Primary sensory networks did not show subacute changes in functional connectivity. One day after ayahuasca administration, there was increased anterior cingulate cortex connectivity within the salience network compared to placebo, which correlated with altered somesthesia scores. Decreased posterior cingulate cortex connectivity was also found within the default mode network, which correlated with altered volition scores. Additionally, following ayahuasca use, there was increased connectivity between the salience and default mode networks, which correlated with altered affect scores.