Martha MacCallum reports that a new study has found that former NFL linebacker Junior Seau suffered from traumatic brain disease because of head trauma. Seau killed himself last May just two years after retiring as one of best linebackers in NFL history.

A team of scientists from the National Institutes of Health analyzed his brain tissue and found this disease, which can cause dementia, memory loss, and depression. Several dozen football players have been diagnosed with traumatic brain disease.

Check out this recent Studio B discussion on the long-term effects of head injuries on NFL players following the murder-suicide incident involving linebacker Jovan Belcher.