Q. My son is 4 years old and is very violent. He has been diagnosed with ADHD and has recently started taking ritalin. He has been kicked out of one daycare and is struggling in his new daycare, where he has been for 1 year. The daycare has hired two paraprofessionals to help him.. I am very concerned about his aggressive, violent behavior. He hurts other children, teachers, his sister and myself. We have tried therapy which has not worked. He has no respect for others and no remorse for most of his actions. Am I alone, or are there other children with the same problems? What is wrong with him? He is a very smart child, but I am so scared of what he will become. The daycare workers are worried that he won't make it in the school system because his violent behavior is so severe.

A. The idea which most doctors follow (or should) is called parsimony of diagnosis. Simply put, your four year old son's aggressive behavior likely is one of many behaviors which are problematic. All of these behaviors likely arise from a single biological cause. There is no advantage to these behaviors, and like all other painful stimuli--burning himself, wearing shorts in the middle of a snowstorm, going hungry, not sleeping--he will change these behaviors to help himself. In the aforementioned examples this would include not touching an iron, wearing a coat, eating food, or sleeping. Since he is getting only negative feedback from his behavior, it is not only illogical to continue if he had any choice in the matter, but out of context with the rest of his life since he changes things that hurt.

The behavior is likely heritable, and thus it is genetic. I would medicate him with the same medications known to be effective in other impulse control disorders, and choose the one which will cover all of his symptomatic behaviors. There is a wealth of data on aggression and treatment in the literature. Most, but not all, good child psychopharmacologists are associated with universities and larger institutions. A good university based psychiatric program would be a good starting point.