The key to getting off painkillers with Jim McMahon. Former Super Bowl champion and Chicago Bears quarterback Jim McMahon says an unfairly demonized drug helped him recover from the pain of his football career: medical marijuana. Now 56, McMahon has been plagued by debilitating health problems following his 15-year career and multiple concussions in the National Football League. He has been diagnosed with early-onset dementia and has severe headaches, depression, memory loss, and vision and speech problems. He also said he suffered a broken neck.