Why did wwe superstar chris benoit suicided?

I saw a long (20 minute) news report on the double murder suicide and a doctor explained that because of the hits Benoit had taken during his career he had the brain of an 80 year old altseimers patient. Supposedly that brain damage coupled with the steroid abuse led to the violent attack on his family and his subsequent suicide. I don't know that for sure it was just on a report I watched.