I've seen stories like that before, it's awful for the family on the periphery, like the brothers and sisters. Most parents will love and be devoted to anything they get, but you can help but feel resentful if your parents have to care for what is basically a baby for 20 years.
On the opposite end, there is this case of an autistic man-child that was becoming such a problem that his family's church had to have a restraining order put on him:
http://www.nbcnews.com/id/24920240/ns/us_news-life/t/mom-fights-church-ban-her-autistic-son/
http://usatoday30.usatoday.com/news/religion/2008-07-01-autistic-church_N.htm
I feel badly for the other four children in the family, they have to keep everything they own separate from their brother to keep it from getting destroyed. Hopefully they will benefit from the experience in their adult lives. I also feel for the rest of the church; I'm sure they aren't unsympathetic to the family's situation, but you can't have a 225 pound man having outbursts like that around children and elderly people.