According to a new resting-state fMRI mega-analysis, psychedelics do not simply make brain networks fall apart. Instead, they most consistently increase communication between higher-order transmodal networks, such as default mode and frontoparietal systems, and sensory or motor networks. In other words, boundaries between normally segregated systems appear to soften during the acute state.
Evidence for broad within-network breakdown was limited and variable across drugs and networks, with the clearest decreases in visual and somatomotor subnetworks. Subcortical changes were most consistent in the striatum, especially caudate and putamen, which showed stronger coupling with cortical systems.
Psilocybin and LSD showed notably similar patterns. DMT produced the strongest apparent disruptions but with greater uncertainty due to smaller samples, while ayahuasca diverged, likely reflecting its pharmacological complexity and limited data. These findings come from healthy volunteers and focus on acute connectivity, with results influenced by dose and analytic choices, as reported in Nature Medicine.
Bottom line: psychedelics most plausibly reconfigure brain communication by boosting cross talk between self-related and sensory systems, rather than causing a general network collapse.