They probably have been taking their lives all along. The knowledge that repeated head traumas can cause suicidality has only been widespread for 10 to 15 year

They probably have been taking their lives all along. The knowledge that repeated head traumas can cause suicidality has only been widespread for 10 to 15 years. Before then for example it was commonly believed even by experts that the only head traumas that can cause permanent problems are those where the victim loses consciousness right after the hit.