Psilocybin (1 mg/kg) reversed long-term brain and behavior damage in rats exposed to 5 days of repeated head injury and strangulation, with improvements seen just 24 hours after dosing. Treated animals showed reduced anxiety behaviors, increased reward response, and stronger memory performance, alongside normalized brain markers like reduced microglial inflammation and restored reelin-positive cells. Blocking the 5-HT2A receptor eliminated these benefits, confirming the exact pathway driving recovery.