e had both our autistic boys on risperdal. The older boy was on quarter the dose his baby brother was on, and doubled his weight in six months. The younger, on the higher dose - no observable weight gain out of the ordinary and no sedation. The older boy would take his pill and fall asleep for hours. Hence the lowered dose. Benefit - minimal. It did seem to smooth out the moods and the peaks and troughs of impulsivity, but the benefits were not sufficient to warrant putting up with the problems (which included the expense).
Both our boys are on stimulant medications and this has helped a lot. When withdrawing form acute doses of stimulants we have found aggression in both boys, especially difficult child 1. Long-acting medications helped, but if he forgot his medications the next day, watch out.
Caffeine intake used to be a huge problem with both boys, far less so these days. I remember difficult child 1 involved in a nasty incident one day when he smashed an empty bottle and went after a kid on the train. The school dished out a really effective punishment (with my permission) - he had to spend the next week after school sweeping up rubbish (including broken glass) on the railway platform. Plus he and the other kid had to resolve their differences, which thankfully they did while waiting in the corridor for the principal right at the start.
We had difficult child 3 on various antidepressants but they have had weird effects on him, including aggression at one point.
These kids also can be VERY frustrated and have a short fuse, sometimes it's not the medications but the kid's poor responses to Life, the Universe and Everything. As the kid gets older into puberty and testosterone kicks in, it gets worse. Especially if they are getting bullied or hassled verbally.
I told my boys that they had to get used to life's double standards. Because they are different, they are held to different (and higher) standards than other people. An average kid can lash out at another kid and get minor consequences, but one of our boys fighting back, defending himself or even reacting in temper will find himself in really serious trouble. It's not fair, but it's life and you have to put up with it. Learn to NOT fight back unless you really have to defend yourself, and if you do then expect to cop it big time. It's not a fair lesson, but it saved my boys a lot of grief because eventually teachers realised that if our kid was hitting, it was in pure self-defence and to look at the other kid first.
Also, other kids learned that it was no fun attacking a kid who wouldn't fight back. Also that our boys were no threat and beating them up was no glory, either. Too much like shooting fish in a barrel - bad sportsmanship.
One last thing the bullies learned - if our kids were provoked beyond endurance, watch out, because they eventually reacted like berserkers. And nobody wanted to be on the receiving end of a difficult child gone totally nutso and not caring how much damage he did.
Interestingly, difficult child 1 now trains others to fight with medieval weapons. To do this they have to hit with the flat of the blade and pull their blows so as not to injure. They do still get injured, but he does this for fun, not in anger. I think I'll have to get difficult child 3 into this as well. Once he passes his driving test...
Marg