Hi....I think that when my daughter was on Abilify she had the same thing happening.....waking up a few times a night with broken sleep.
When does he take the Abilify??? Sometimes just changing the time he gets it or taking it in divided doses may help. My daughter seemed to get more sedated on it during the day and no matter what they did, either by decreasing it or adjusting the times, she just continued with the sedation. Eventually, they took her off of it. What dosage is your son on???
I would defintely bring this up to your doctor. If the med is working well otherwise, perhaps adding some Seroquel or another med at night will help with his sleep. There is a natural med called Melatonin....it comes in I believe 3mg tabs. You could try giving him a half a tab and see if that helps. It is a natural chemical released in the body that helps with sleep and will not leave a groggy feeling. You can find it in the vitamin section of the store. I tried it and it does work well...give it to him about a half hour to an hour before bedtime.
Also....alot of kids with BP have anxiety especially at nighttime. So that may be what is going on with your son and eventually they may have to perscribe something for that as well.
Hope this helps....and do take care of yourself. Catch up with some sleep while he is in school if at all possible.
((((HUGS)))) ~ Goody