I agree with smallworld, his medications are probably not where they need to be. We all hate to medicate our children....believe me......I was miss organic Mom until my difficult child was 6 and tearing the world apart.........I finally realized he was so unhappy, and just like an ear infection, it was my responsibiliy to help him feel better.
An anti depressant can make your son very, very impulsive and odd, if he has any sort of mood instability. Abilify can also sometimes have insomniac like results, and in some cases (like ours) make kids more manic. 125 mg of Depakote is like taking an aspirin, I would think it would do none to nothing. I would find a good psychiatrist, have a good neuro pysch evaluation, and try some different medication combos. For us, it was medication after medication until we found Lithium - and then it was like a new beginning for my son. You just have to be diligent and determined to find the best fit for your child.
As far as the stomach aches, it sounds like a stress related issue. Is the end of school testing, etc getting to him?