In 1998, the former heavyweight champ was ordered by the Nevada Athletic Commission to have an evaluation to see if he was mentally fit to box again. Tyson had become infamous for his violent behavior and lost his boxing license after biting a chunk out of Evander Holyfield’s ear during a 1997 bout. He also spent three years in jail for rape. The evaluation found signs of almost lifelong depression and neurobehavioral issues including attention, memory, and impulse control problems. Tyson began taking anti-depressant drugs after the Holyfield fight, but his troubles continued.