A friend of mine is the official statistican for Southport Football Club. About twenty years ago he wrote a book that interviewed every surviving player that had played league football for Southport. He went all round the world meeting ex players who had mainly played in the 1960s and early 70s.
He remarked back then how many of them were either living in care homes or were being cared for by relatives. Mainly because of forms of dementia. It was by no means a scientific study but my friend reckons more than half of the men he met were mentally impaired to varying degrees.