Kenneth Iwamasa, Perry’s live-in assistant, purchased at least $55,000 worth of ketamine for the actor, prosecutors said. The 60-year-old agreed to plead guilty to one count of conspiracy to distribute ketamine and will be sentenced Nov. 19. LOS ANGELES —…

These structural changes not only explain behavioral shifts in addiction but also underscore the need for early intervention to prevent long-term damage and support recovery. The parts of the brain that control addiction are the prefrontal cortex, amygdala, and ventral…