If the anger issues started or worsened after he astarted the Strattera, the med could be the problem. There have been posts on this board from other parents whose kids had severe behavior changes after starting on Strattera (mine included) - try doing a search. Please discuss the possibility with your child's Dr.; there are so many other meds out there. Strattera is the only non-stimulant med for treating ADD/ADHD, but that does not mean that it is any less likely to cause side effects. My son spent every day in the Principal's office while taking Strattera (as a 2nd grader) because he could not function in the classroom. He was paranoid, disruptive, having temper tantrums and making threats to the teachers. By the time I figured out it could be the medication, they were recommending I put him in a special ed. class. It took several weeks to get it out of his system, then he was back to his sweet, cooperative (but hyper, inattentive and disorganized) self. He is doing much better on the short-acting Ritilan, and it is worn off by bedtime.