The boy you are talking about was Steven Stayner. He was kidnapped through trickery and force on his way home from school. The kidnapper took him in as his son and also sexually abused him for a period of 8 years. Steven came out of hiding only in an attempt to rescue Timmy White who had been recently kidnapped and added to his family.

I also immediately thought of the Stayner case when I heard of the resolution of this one. However, when Steven was kidnapped he was 7 years old and the kidnapper was able to convince him that his parents no longer wanted him. I'm not sure you can convince an 11 year old of something like that. This case has some parallels, but it also certainly has differences.

On a side note, Steven wasn't the only person with severe psychological issues in his family. His brother, Carey Stayner, went on to become a serial killer.