I was on 2mg of Risperidone for around 6 months... I decided I wanted to try coming off it & talked to my p-doc about it. He was happy for me to do so & advised me it was ok to stop at that dosage without tapering down. Bear in mind that 2mg is a fairly low dose to begin with anyway.

I didn't have any noticeable "withdrawal" effects although my voices did get a bit worse after a couple of weeks for a month or so but have quietened down now.

In terms of switching from one AP to another, when I tapered from Abilify to Risperidone, it was very fast. I similarly did a low dose for 1 week followed the next week by the starting dose of Risperidone. In that circumstances, I had absolutely no ill effects or worsening of symptoms.

I'm sure the p-doc does know what they are doing. I'm sure your step son will be ok...