Some are using fibroblast growth factor. Others are also using antivirals. We do use SSRI's and they can be very helpful. For an 11 year old, I would probably start with 25 mg of Zoloft or 10 mg of Prozac. Luvox is sometimes considered the drug of choice when there are many obsessions and compulsions.
Viral infection is plausible.
Post-vaccination damage is also a possibility. Unfortuntely there are more questions than answers. IN spite of this, we do manage to help many children.