Based on the evidence I've been given, I believe the root of Henry's problem to be that he is a Schizoid. I base this on a number of things. The first, being that while he does have a family he seems to care about, he simply does not. He only seems to care so he can get what he wants from his family. He does not desire a close relationship with any member of his family, because if he did, he would not have been so eager to hurt members of his family for no real reason. 

Another key point is that he had no friends, other than when Mark showed up, which also leads me to believe that he was a very solitary person. The solitary activies assumption is justified by the fact that he spent a lot of time in a tree house so high that it would have discouraged others from joining. He also seemed to like the idea of having a friend right when Mark showed up. A schizoid is also emotionally cold, which is obvious in Henry's case, as he showed no emotion after killing a dog, or his brother, and an attempted murder at his mother and sister. He was also impartial to criticism, especially from his mother, be it good or bad. Or in other words, nothing verbal affected his mood. Example being when Mark flat out told him he was crazy.

Henry also shows signs of being Antisocial. He breaks the law, as demostrated by breaking windows, killing and attempted murders, along with a lack of remorse of the aforementioned. He also smoked just because he wanted to, which is another sign of antisocialism. Henry had no real reason for smoking, and since no one in his family was ever seen smoking, it can be inferred that he also had to steal the cigarets. Henry was always placing himself in dangerous situations or places, such as his treehouse. Many times you could see him walking along ledges, or the time he actually sat beside 'Mr. Highway' on the overpass. He placed his face right next to an obviously vicious dog without flinching. Another antisocial characteristic he shows is his persistant deceit to gain what he wants and maniupulate, especially evident with his mother. Even in the end, instead of begging for his life, he was trying to manipulate his mother into saving him, as opposed to saving Mark.

Henry showed a lot of signs of other disorders, but only enough of a certain type for me to be able to classify him as one more thing; sadistic. In some of the earlier parts in the study, Henry attempts to establish dominance over his sister, epecially noticeable in the instance where she comes into his room and he grabs her by the ears and tells her she isn't to be in there. Something extremely notable with Henry, is the way he tries to discipline Mark by hurting the people Mark cares for. When Henry found out that Mark cared about his sister, Henry took efforts to harm her, at her's and Mark's expense. The same thing happened with Henry's mother. 

Another thing that denotes Henry's sadistic behavior is the pleasure he takes in causing harm to others, such as the dog, and most of all Mark. He also brings up things to his mother to hurt her mentally, such as stating that Mark wanted to stay in Richards room when he knew it would upset her. Sadistic people can also be facinated by weapons, violence, and death, which he cleary was. He asked Mark questions about his mother's death, and even stated a few things he noted about his own brothers death. He was so facinated by weapons that he even made his own crossbow, which is used to kill a dog just as soon as he got it working right.

Etiology: All of Henry's problems seem to have been strung from a jealous he had of his younger brother, Richard, or possibly when his sister was born. The incident in the shed where Henry overreacted about the rubber duck seems to justify this point. Another one of his problems is that his parents would not check on what he was doing for the longest time. Only near the very end did his mother check on his shed. He stated on one instance that he could do whatever he wanted and no one would stop him.