I agree. I don't think the adhd is not the issue and it is true that many kids with adhd have some social skills problems and find younger kids easier to deal with. However, that is a huge age difference. What exactly does a 14 year old still "play" that would interest a 7 year old. We had an 11 year old that lived close to us that jumped on the trampoline with my young boys (then age 4/5 and 5/6). But I wouldn't let them go off and play by themselves. So, I don't think it is ideal as it is a big age difference. Running around in the yard, playing a neighborhood game, etc. okay. But true play mates, it would be better for your son to look for age mates. Just my opinion.
Well I dont think the ADHD would be a problem unless the child is prone to rages, personally I would supervise the play, the age gap is large and it may be good to encourage your child to play with children nearer his/her age group .good luck
That is quiet the age difference. My son is 8 and I don't let him play with anyone over the age of 10 because there is such a contrast difference in the maturity. Although the 14 year old may seem immature, they are more aware of everything and they know a lot more things that 7 year olds need to know at their age.