9 year old son anger issues

I am concerned about my 9 year old stepson's angry outbursts.  His parents divorced a couple of years ago after mom took him and his little brother to Iowa in the middle of the night without a word to dad.  Dad now has primary parenting time with joint decision making, although they are currently in the middle of a custody hearing again (at mom's instigation).  I have been in the picture for about a year.  Over that time, I have seen this child throw violent outbursts over the simplest of things, which usually include him not getting his way.  In the beginning, dad gave into him almost everytime, for fear of losing him to mom.  Dad has gotten more consistent, and the outbursts have become fewer.  We notice them now mainly when he is tired.  The most recent fit included throwing things, hitting and pinching little brother, mild cursing at dad, telling us we're just trying to be big mean jerks to him, and lots of yelling and screaming.  When dad and I try to institute discipline for disrespect, usually a time out equal to age, he fights back and says its not fair, he just got upset and doesn't realize how he's reacting.  I really think this is true, but it is hard to maintain consistency while still letting him know that we're trying to help him.  Some more background info:  as a small child, this little boy primarily did what ever he wanted with no discipline.  He was diagnosed with ADD this past spring and the psychologist reccommended a trial medication.  Dad agrees, but mom does not, and called the doctor's profesionalism into question, so he will no longer work with us.

My question is, what can dad and I do to help this precious child?  We recognize there are problems, and really want to help him, but seem to be thwarted by mom who is claiming it's all because he's living with us.

[Kevin Kennedy, Ph.D.]

In light of all that you mentioned, it's no wonder he poses behavior problems. If, on top of that, he has an untreated neurological condition like ADHD, it will only exacerbate the situation. Stay on the course of systematic, consistent management of the behavior, and keep up with efforts to have him treated for his ADHD. For help with management, rely on SOS Help for Parents by Lynn Clark (see www.sosprograms.com).