The question comes up all the time. My child has Asbergers,or ADHD, or oppositional disorder or... you fill in the blank.
I can share from personal experience... YES! It takes consistency and determination on the part of the parents and may take a little longer for a special needs child but the anser is absolutely, it does work. In fact, this is probably exactly the kind of brain and life skills training they need.
Here are 2 really great CDs for parents. They were meant for use by teachers but really, they are quite helpful for parents too. (You can also give them as a gift to your child's teacher)
and more http://www.loveandlogic.com/ecom/c-13-favorites-of-educators-and-other-professionals.aspx.
Love and Logic also has great materials for parents of children with medical challenges/
Health Issues: http://www.loveandlogic.com/ecom/p-330-parenting-children-with-health-issues.aspx