There is evidence that some cases of obsessive compulsive disorder and tic disorders such as Tourette's (and possibly ADHD, chorea and myoclonus) may be caused by antibodies attacking specific areas of the brain.
NIMH Diagnostic Criteria:
- Presence of OCD or tic disorder
- Onset between age 3 years and the beginning of puberty
- Abrupt onset of symptoms or a course characterized by dramatic exacerbations of symptoms.
- The onset or the exacerbations of symptoms is temporally related to infection with group A beta hemolytic streptococcus.
- Abnormal results of neurologic examination (hyperactivity, choreiform movements, tics) during an exacerbation.