Well it depends. Risperdal is an antipsychotic and it is effective in treating psychosis. Asperger's is a developmental disability and thus doesn't specifically respond to antipsychotics. What is the Risperdal specifically being used for? Also there is a community specifically for Asperger's.
I must disagree with the other poster. Risperdal was approved by the FDA for use in children on the spectrum in 2006 to treat *repeated* bouts of aggression and irritability as are other anti-psychotics. My son was diagnosed with Asperger's when he was 3 and has been taking Risperidone (Risperdal) for 4 years in varying dosages. Without it he could not have attended mainstream schooling as his aggressive outbursts were a danger to himself, other children and adults. I accredit the Risperidone with taking him from a core of "Fight or Flight" to being able to tolerate his environment to the point that he could not only be taught/learn but now wants to be social, is maintaining friendships and plays with other children willingly. He is also functioning at or ABOVE his peers academically. However, like many people who take Risperidone, he now has mildly elevated levels of prolactin (it's what causes women to produce milk) so we will be reducing the dosage and trying something else, which disappoints me because finding ANYTHING that works with my son is extraordinarily challenging. It has been a nearly miraculous drug for us, so I recommend at least trying it, modifying your child's diet if weight gain is an issue, and checking blood labs yearly.
We were just prescribed this for my son who is 8. He spent the last 3 years fighting outbursts which included throwing things, hitting others, screaming, crying, and not being able to cope with things he didnt like the answer to. He started Trileptal in August and we saw huge improvement. but 2 months ago the doc added Guanfacine and Clonidine to help. then things became bad again. And guanfacine is not easy to come off of. We lately we have had outburts like previous to trileptal. and so he has presrcibed the Risperal. we are nervous about what we are reading for side effects including males developing breasts and milk. we are looking for someone who has used it a while in a young boy.