CTE had an earlier name called dementia pugilistica ("boxer's dementia") or punch-drunk syndrome, because it was originally thought to be limited to boxers and not other athletes. It was later found that Football players, wrestlers, ice hockey players and military servicemen also had the same form of dementia. In 2005, Dr. Bennet Omalu and his colleagues discovered CTE in football players. There was a film based on his CTE discovery story called Concussion

Repeated concussions on the head can cause serious damage to the human brain. Brain damage can lead to mood swings, depression, irrational or erratic behavior, etc. Many of the people who had CTE were depressed to the point they took their own lives.

Whenever I watch a boxing or wrestling match, I wonder whether those boxers and wrestlers will be fine after taking a blow on their head?

The only people with CTE who killed a person were Chris Benoit, Aaron Hernandez and Jimmy Snuka. Did CTE impair their judgment? Or were they monsters before they had their heads hit over and again? Most of the people with CTE have never killed a person.

I find it odd that superheroes in comic books received concussions on the head while fighting crime and still have no mental health problems. But it's fiction after all. PTSD also scarcely exists in the Superhero world.

https://en.wikipedia.org/wiki/Chroni...encephalopathy

https://en.wikipedia.org/wiki/Bennet_Omalu

https://en.wikipedia.org/wiki/Concussion_(2015_film)