Skip to content

Rafael Faria Sanches

Universidade de São Paulo

8 papers in the library · 2,155 citations · publishing 2015-2020

Papers

Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial

Psychological Medicine June 15, 2018 Fernanda Palhano-Fontes, Dayanna Barreto, Heloisa Onias et al. 827 citations

A single dose of ayahuasca reduced depression severity more than placebo in patients with treatment-resistant depression. Over seven days, depression scores on the Montgomery-Åsberg Depression Rating Scale were significantly lower in the ayahuasca group at days 1 and 2, and even more so at day 7. Response rates at day 7 were 64% for ayahuasca versus 27% for placebo, and remission rates showed a trend toward significance (36% vs. 7%). Effect sizes grew from day 1 to day 7, indicating sustained improvement. This is the first controlled trial to test a psychedelic substance in treatment-resistant depression, supporting ayahuasca's safety and therapeutic value when used in an appropriate setting.

Antidepressant Effects of a Single Dose of Ayahuasca in Patients With Recurrent Depression

Journal of Clinical Psychopharmacology December 11, 2015 Rafael Faria Sanches, Flávia de Lima Osório, Rafael G. Dos Santos et al. 468 citations

A single oral dose of ayahuasca, an Amazonian brew containing dimethyltryptamine and harmine, produced fast-acting and sustained reductions in depression severity among 17 patients with recurrent depression. Scores on the Hamilton Rating Scale for Depression, Montgomery-Åsberg Depression Rating Scale, and Brief Psychiatric Rating Scale decreased significantly from 80 minutes through 21 days after intake. Brain imaging showed increased blood flow in the left nucleus accumbens, right insula, and left subgenual area—regions involved in mood regulation. Vomiting occurred in 47% of participants, but no other adverse effects were reported. The authors suggest ayahuasca may have antidepressant properties but call for replication in randomized, double-blind, placebo-controlled trials.

Long-term use of psychedelic drugs is associated with differences in brain structure and personality in humans

European Neuropsychopharmacology January 16, 2015 José Carlos Bouso, Fernanda Palhano-Fontes, Antoni Rodrı́guez-fornells et al. 221 citations

Regular use of the psychedelic brew ayahuasca is associated with thinning of the posterior cingulate cortex (PCC), a key hub of the default mode network. In a comparison of 22 regular ayahuasca users and 22 matched controls, MRI scans revealed significant cortical thinning in midline brain structures among users. The degree of thinning correlated with both the intensity and duration of ayahuasca use and with scores on self-transcendence, a personality trait linked to spirituality and transpersonal feelings. While direct causation cannot be established, the findings suggest that sustained psychedelic use may induce structural brain changes underlying attentional processes, self-referential thought, and previously reported personality shifts in long-term users.

Effects of Ayahuasca and its Alkaloids on Drug Dependence: A Systematic Literature Review of Quantitative Studies in Animals and Humans

Journal of Psychoactive Drugs May 26, 2016 Amanda Amorin Nunes, Rafael G. Dos Santos, Flávia de Lima Osório et al. 92 citations

Ayahuasca, a hallucinogenic beverage containing DMT and β-carbolines, shows potential for treating addiction. A systematic review of five animal studies and five observational human studies found that ayahuasca or its components improved biochemical or behavioral measures related to drug-induced disorders. Four of five human studies reported significant reductions in dependence symptoms or substance use; one found no significant effect. The anti-addictive mechanisms are unclear but may involve peripheral MAO-A inhibition by β-carbolines and central 5-HT2A receptor activation by DMT in brain regions regulating mood. Controlled studies are needed to confirm these preliminary findings.

Long-term effects of ayahuasca in patients with recurrent depression: a 5-year qualitative follow-up

Archives of Clinical Psychiatry (São Paulo) February 1, 2018 Rafael G. Dos Santos, Rafael Faria Sanches, Flávia de Lima Osório et al. 37 citations

Ayahuasca, a botanical hallucinogenic preparation containing β-carboline alkaloids and DMT, was well tolerated by patients with treatment-resistant major depressive disorder in an open-label trial. Symptom reductions lasted only a few weeks, but most patients considered the experience among the most important of their lives, even 4 to 7 years later. This is the first long-term follow-up of a clinical sample from an ayahuasca trial, suggesting that while acute antidepressant effects are short-lived, the subjective significance endures.

A randomized placebo-controlled trial on the antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression

bioRxiv (Cold Spring Harbor Laboratory) January 27, 2017 Fernanda Palhano-Fontes, Dayanna Barreto, Heloisa Onias et al. 22 citations preprint

A single dose of ayahuasca produced significant antidepressant effects in patients with treatment-resistant depression compared to placebo. Depression severity, measured by the Montgomery–Åsberg Depression Rating Scale (MADRS), was significantly lower in the ayahuasca group at one, two, and seven days after dosing. Effect sizes increased over time, reaching a Cohen's d of 1.49 at day seven. Response rates were significantly higher in the ayahuasca group at day seven (64% vs. 27%), and remission rates were marginally significant (36% vs. 7%). This controlled trial supports the safety and therapeutic value of ayahuasca in treating depression.