Could my child have aspergers?

My child is 7years 7months old he was diagnosed with ADHD at age 5 but I have often wondered if he had Aspergers? He rocks to clam himself down even banging his head sometimes. He did have speech therapy in kindergarten, however, the therapist suggested that he no longer needed it. his fine and gross motor skills are age appropriate and he is doing well academically, though he is in special ed classes. he doesn't interact much with other children, only his sister whom he is very close to. He doesn't like loud noises. In class he often makes noises and picks his finger nails until they bleed. when he is frustrated he rocks, throws things, opens up cabinets, drawers, pulls things out of his desk, he has been known to smack other people if they bother him. the school tells me that he does have some social delays but what could be causing it? He also plays with one toy at a time and prefers to play alone.  

[Kevin Kennedy, Ph.D.]

He shows developmental difficulties in a number of areas, incl. cognitive, social, emotional. It's not clear on the basis of your description that he meets crietia for AD, but I would certainly recommend an evalaution by a developmental pediatrician.