In the UK Daily Mail online their report indicates the 20 year old Lanza was mentally disabled.
I saw another report that said Adam was an honor student in 9th grade. Of course, false reports have been issued by NBC and CNN. There was an interview with somebody who claimed to be a friend of the brother Ryan. He said Ryan was into arts and video games and never talked about Adam or his parents. When he was asked it did not seem odd that he never spoke about his family, the so-called friend said, “No.”