ColleenB,
I once asked a psychologist how can I tell the difference?
For example, if my son didn't do something important like go to a dr's appointment.
Is is because of ADHD, because he can't remember the appointments (learning disability), because he's depressed (mental illness) or because he's high?
If I could tell the difference then I would know when to help and when not to help.
At the time, his answer annoyed me but on reflection it started to make more sense.
He said, "Who cares?"
His point was, there are some things my son is not capable of it might be because of his disabilities or his drug use. At the end of the day, I have to decide for myself which things are important to me to help with.
I guess my point is, it sounds like your son needs some help. Hopefully, he'll get it and it won't matter which came first.
Good luck.
We're not alone.