i had this type of behavior as a child and was taken to a psychiatrist. won't bother with the details but i couldn't control the fears/acute worry i had. that was quite a long time ago (!) but in my case my dear father was a perfectionist and his imposing his high expectations on me set the behavior off. i'm not saying this is the case with your son because a lot of things can be the catalyst as you stated. if the doctor that's seeeing him now doesn't seem to be helping i too suggest you consider seeking other help for your son. in my case the solution was presented to my father and it helped tremendously with me not having full blown OCD as a child.