I am a psychologist and have written articles and a book about anger overload. There can be different underlying causes. Feel free to e-mail me after reading other parents' questions on my blog (you can access it from http://yourdefiantchild.com. Many of these children have delays in developing cortical controls for anger. Sometimes the children get misdiagnosed with bipolar disorder and are put on major medications. I suggest strategies for parents instead, but the key is to first figure out the underlying cause. Look at my blog, article or book for how to do this.