Hi and welcome! SPD and ADHD do often go hand in hand. They have many overlapping symptoms. My younger son looks ADHD, but is just a sensory seeker SPDer. He never sits still, must touch everything, loves to be squeezed in bear hugs, etc. He doesn't sit next to you, he sits on you. And he loves twirling my hair, which I don't mind.

You might want to try heavy muscle work with him. Have him get the gallon of milk from the fridge, carry heavy books from room to room, bring the laundry basket of dirty clothes to be washed. You could have him do wheelbarrows (hold his legs while he walks on his hands) down the hall. Any gross motor movements that use muscle work.

Do you have a weighted blanket for him? My younger son sleeps under his weighted blanket every night. My older son sleeps under his most nights. (We had so many sleep problems for years.) Maybe try a weighted vest.

Also, my boys do best when they know exactly what is expected of them. I tell them the behaviors that are acceptable every time we go somewhere new and even tell them at later times as reminders. If we're going to a restaurant, I tell them, Quiet inside voices, walking feet, hands to yourself, no climbing, no wrestling, no hitting. Everything I can think of that would be appropriate for the situation. I make them repeat back to me how they will act. If its a playdate, I talk about how we act with friends.

Maybe try fidget toys too for some situations. But I really think a weighted vest would help him.

Welcome to the site!