A scoping review of 24 articles found that four psychedelic drugs—ayahuasca, psilocybin, LSD, and the entactogen MDMA—consistently alter brain functional connectivity in healthy individuals. The drugs decreased connectivity within the default mode network and increased sensory and thalamocortical connectivity. These neurophysiological changes correlated with subjective experiences such as altered consciousness, mood elevation, and mystical experiences, suggesting a brain network basis for the drugs' psychological effects. The review provides a potential neural mechanism for psychedelics' subjective effects but notes that direct clinical evidence is needed to advance therapeutic outcomes.
A review of 20 studies examined whether psychedelic drugs can affect social cognition in people with psychiatric or neurodevelopmental disorders that involve cognitive impairment. The drugs studied were ketamine, MDMA, psilocybin, LSD, and ayahuasca, tested in depressive disorders, anxiety disorders, autism spectrum disorder, and post-traumatic stress disorder. Findings included neural activation patterns suggesting that ketamine and psilocybin may modulate processes relevant to social perception, especially facial emotion processing, in depressive disorders. MDMA was linked to improvements in self-reported psychosocial functioning, self-awareness, and self-compassion in participants with PTSD. Direct evidence of improved social-cognitive functioning remains limited.