Study Summary

In a case series, 17 volunteers with a current depressive episode in an inpatient psychiatric clinic received a 2.2mL/kg dose of Ayahuasca. Patients were assessed using the Hamilton Rating Scale for Depression, the Montgomery-Asberg Depression Rating Scale, the Brief Psychiatric Rating Scale, the Your Mania Rating Scale, and the Clinician Administered Dissociative States Scale. Blood perfusion of the brain was assessed using single photom emission tomography. An increase in psychoactivity was seen in the acute phase, and decreases in depression were seen following ayahuasca administration, and were maintained to day 21. Increased blood perfusion was seen in the left nucleus acumbens, right insula and left subgenual area. Vomiting was reported in 47% of patients.