Researchers from the Universidade de São Paulo (USP) and ICEERS have found that ayahuasca may modulate neural networks, and suggest that more research is needed to potentially lead to innovative treatments for mental health conditions.
The use of ayahuasca dates back centuries in South America. The traditional brew’s psychoactive component is DMT – often from the Psychotria viridis vine.
Much like other hallucinogens, ayahuasca affects mood and self-perception, however, its mechanism of action is currently unknown.
Findings from research so far suggest that there may be a connection between the effects of hallucinogens and the modulation of the Default Mode Network (DMN) – a network of the brain associated with activity such as daydreaming and self-reflection.
As highlighted in a 2014 study by Robin Carhart-Harris et al: “DMN connectivity increases during mental time-travel (Andrews-Hanna et al., 2010; Martin et al., 2011) and activity in the medial prefrontal node of the DMN is reliably elevated in depression (Farb et al., 2011; Lemogne et al., 2012).
“These findings strongly implicate the DMN in introspective thought and suggest that hyper activity and connectivity in the DMN is related to a certain style of concerted introspection.”
For this systematic review of human studies, the ICEERS and USP researchers selected studies with neuroimaging results related only to human ayahuasca consumption. These included observational, case-series and clinical trial studies that analysed acute, subacute or prolonged effects of ayahuasca.
The findings revealed a correlation between the use of ayahuasca and different neuropsychiatric factors, which the researchers say linked reductions in DMN activation to acute, subacute and prolonged antidepressant effects.
The researchers say that the findings demonstrated that local neural networks appeared to become expanded, while overall brain connectivity declined, whereas, with chronic consumers, anatomical changes were reported, most notably related to cingulate cortex.
Speaking to Psychedelic Health, study researcher, Rafael Guimarães dos Santos, commented: “I think the most relevant finding is the congruence of data derived both from acute and chronic studies, using molecular (SPECT), structural (MRI), and functional (fMRI) imaging, showing that ayahuasca modulates frontal and paralimbic areas related to introspection, self-consciousness, social cognition, and emotional processing.
“These areas include key structures of the DMN. Overall, these effects are similar to those observed with other hallucinogens such as psilocybin and LSD, suggesting that they are probably related to DMT in ayahuasca, although we cannot ignore the possible effects of the beta-carbolines present in ayahuasca (ayahuasca is not equal to DMT).”
Such effects of beta-carbolises may include hallucinations, vomiting and confusion, among others.
While the results are preliminary, the researchers say the findings warrant further studies – potentially paving the way for new treatments for mental health conditions.
