I supppose the issue is whether he's socially struggling/isolated because he's much smarter than everyone else or whether it's because he's also got ADHD. It's tricky because social difficulties are common with ADHD (missing social cues etc) and increasing the social demands by academic acceleration may not be the best idea.
My gifted DD befriends kids who are also smart, she's in a cohort of 3 in her year (of 100 kids) where they do accelerated maths which is about 2-3 years ahead and they all get on really well. They also have other friends in the class and through extra curricular events. I suppose I'm saying that I don't think being very smart necessarily has to be synonymous with friendship difficulties. DD's best friends are the other smart kids because she says she can talk to them about anything - but she also has kids she likes through swimming, drama etc.
I found my DD's academic boredom was alleviated by her pullout maths (her steength) combined with a whole heap of sport. With the added bonus that she made the school swimming team and so made friends through there.
Could you aim for some good enrichment and an absorbing extracurricular activity?
