Risperdal for Tantrums My 29 yr old son is autistic had a generally angelic disposition, but was prone to tantrums if he was frustrated or angry. He'd bellow, shriek and throw things when he had a tantrum. He'd also bellow, shriek and hop on both feet when he'd have one in public. His neurologist prescribed Valium to stop a tantrum after it already started, but then he prescribed Risperdal, 1mg. twice a day. This was to be gradually increased, but when we did Jimmy was so dopey and sleepy he couldn't function, so we went back to 1mg. twice a day. This completely stopped the tantrums with no side effects and now he always has his angelic, sweet disposition and is happy all the time. I can't praise Risperdal enough for how much it has helped Jimmy.