MDMA (ecstasy) produces prosocial effects such as sociability and empathy, consistent with user reports. In rodents, MDMA increases passive prosocial behavior and social reward while reducing aggression, possibly through serotonin 1A receptor-mediated oxytocin release interacting with vasopressin receptor 1A. In humans, MDMA raises plasma oxytocin, fosters feelings of social affiliation, reduces recognition of negative facial expressions (cognitive empathy), blunts responses to social rejection, and enhances responses to others' positive emotions (emotional empathy) while increasing social approach. These neurobiologically complex prosocial effects likely motivate recreational ecstasy use.
About 40% of people with major depressive disorder have cognitive impairments, and those with treatment-resistant depression (TRD) often show such deficits. Ketamine, a rapid-acting antidepressant, may help. A systematic review of five studies found that a single low-dose intravenous infusion (0.5 mg/kg) did not worsen cognitive function. Some studies reported improvements in working memory and visual learning after ketamine treatment, while gains in processing speed and verbal learning occurred only in anxious TRD patients. The evidence suggests ketamine may have pro-cognitive effects in TRD, but more research is needed.
Consciousness likely evolved as an adaptive trait, and its subjective reality cannot be separated from its physical neural correlates. Combining anthropology and neuroscience, this review refutes common fallacies that ignore the evolutionary origin of consciousness or that divorce neuroscience from behavioral science. It describes experience as an ongoing overlap between intrinsic neural dynamics and external stimulation, framed as stochastic dynamics of a control system. This supports a world-brain research program and a naturalistic science of consciousness, grounding qualitative feelings in quantitative description and affirming a realistic ontology where physical and subjective aspects are inseparable.