Did your son have tics during the visit at McLean or did you disclose them? I ask because I was told by admissions they would be unlikely to admit my son because he had tics. Just thought I'd mention since you seem unsure of why he didn't get in. I wish I could offer some suggestions but I don't really have any without meeting your son to understand how his ADHD impacts him. But I wanted to say that I sympathize. My DS was just miserable in MCPS with LD. He had a great IEP but it wasn't followed. Maybe an educational consultant could be of help.

Look at Lab. Worth checking out if anything. You need to see for yourself.