Any parents of older teens with ADHD?

[Foursonz]

  My 19 year old was a good student in high school and then withdrew from college due to drug abuse (another topic).  His psychiatrist says he has ADHD and wants to put him on Adderall (sp?) when he returns to school next semester.  He is impulsive and has always been energetic.  I never saw him as having "crazy" energy -I guess because we have 4 sons and I'm used to boys.  Can he have ADHD if he was able to graduate with an B average from a private school but he is definitely impulsive? I thought one of the signs is not being able to concentrate.  Apparently he can when he wants to.  
Thanks for your help

[Sandman2]

   this is the ADHD site.  I would assume you wanted to post to the anxiety site?

[zindel8847]

I suddenly feel anxious if I have to take something out of my bag or if someone calls me and I turn my head, or if I have to rush somewhere, it gets me so anxious... and gives me a slight dizzy feeling
Or If I'm alone with my friend and there's an awkward silence, or if she is following me in the mall, I hate that feeling so bad.