Ex-NFL player Aaron Hernandez suffered Stage 3 chronic traumatic encephalopathy, the most severe case ever discovered in someone his age, The Washington Post reported Thursday. The disease, which is caused by repeated brain injury, would have affected his decision-making, judgment, and cognition. Hernandez, a former New England Patriots tight end, committed suicide in April at age 27. He was serving a life sentence for the 2013 murder of his friend Odin Lloyd. Dr. Ann McKee, the head of Boston University’s CTE Center, said Hernandez’s brain is “one of the most significant contributions to our work” due to its young age. The disease, which can only be diagnosed after the person has died, had not been seen before in someone younger than age 46.