@YARNLADY Have you considered putting him in public or private school? Just as something else to try? I think public would likely be better in his case. I have nothing against homeschooling, I think it’s a great option for some kids. Preferably, a school that doesn’t have a ton of homework. They seem to vary quite a bit.
In my experience depression in young people is often rooted in loneliness. Another possibility from what you described, he might be having trouble learning, and that I think it could cause him to be depressed and lash out. I dint remember if you said if he does well in his studies?
Since he’s 11 would he still be in elementary this coming school year? That might be an easier transition than middle school. If it isn’t helpful you just go back to homeschooling.
If you choose to try it, I guess you have to make it so he doesn’t feel you are sending him away, but rather that he will get to try something new and be with friends, and they have music and art and play outside after lunch, or whatever might entice him to give it a try.
Does he take medication for his ADD? I feel like I might not have read the information well, my apologies if you answered that before.
If not school then some sort of social activity with others or volunteering where he can feel utilized and look forward to it.