Just re-watched the JJ episode. He definitely is supposed to be "low-end Autistic, Aspergers" as described in an evaluation he reads after coming home from his doctor visit. I don't want to give any spoilers so I will just say that the writers makes sure they hammer in the symptoms. He has "rage incidents and mentions that he can only wear 100% cotton because synthetics bother him. He also has an anxiety disorder. When he tells his doctor he is still constantly worrying, the doctor tells him, "just don't do that!) All the doctor wants to do is throw more drugs at JJ. Don't we all know that experience? As with most media portrayals, everything is exaggerated. I think that happens because the writers are trying to show a typical Aspie and can't be subtle about a condition that has many variations.
JJ desperately wants to be normal and accepted by his friends but they are all so wrapped up in their own little dramas that he is sort of their shadow, ruffling his hair as if he was their puppy.
I can't say that I've liked Series 3 as much as I did Series 1. Series 2 was only OK. I found it over-dramatic. It became too much a teen soap opera. I'm not feeling the chemistry with this new cast as I did with the first. Most of them are truly unlikeable. If I were JJ, I wouldn't want this crowd to be my friends. I will wait and see how Series 4 plays out. Maybe it will be better.