Increasing behavior problems in 8 year old son

My 8 year old son has been exhibiting increasingly alarming behavioral problems.  He is intensly jealous of his 4 year old sister and they fight constantly. He has also started to cut his clothes. He says he is angry, mostly at himself, and that he doesn't like himself. When we try to correct a negative behavior, he flies off the handle, then says we don't love him and he doesn't love himself. In fact he has even said he doesn't care if he dies. He does very well in school--reading at the 8th grade level, performing at the 7th grade level in math--and he does this without prodding from us (in fact, it takes him no effort to achieve these levels). He is also very well behaved in school, quiet in class, respectful of the teacher, knowing to stay away from other kids who cause trouble and to stay out of situations where he might get mixed up with the wrong crowd.  When he's home, it's another story! Also, he seems to be unable to control his behavior when we go out in public. Taking him to the store or a restaurant is exhausting because he's constantly moving, making noises--much more so than a "normal" 8 year old.  HELP!!

[Kevin Kennedy, Ph.D.]

Dear Lori,

Your son's symptoms, particularly the cutting of clothes and his suicidal talk, are indicatuions that you should seek a mental health evaluation for him. The instability at home and in some public settings indicates that he might be displaying a mood disorder. If so, this requires treatment. I would not attempt to manage this solely within the home. Dr. KDK