Hello: My 10 year old son has been on concerta for the past 2 years for ADD. He is presently on 36mg/day. It has worked very well for him in school and with the anxiety he was having because he couldn t focus. Two days ago he started having these uncontrollable movements with his head/neck. Like a tic. I didn t give it to him today, but he s still doing it. Could it be from the concert-or should I be worried about something else?