Anti-Purkinje cell antibody as a biological marker in attention deficit/hyperactivity disorder: a pilot study.

An autoimmune hypothesis has been suggested for several disorders in childhood. The aim of the study was to clarify the role of the cerebellum in ADHD and to evaluate the possible association between anti-Yo antibodies and ADHD. The presence/absence of antibodies was tested by indirect immunofluorescence assay on 30 combined subtype ADHD children, on 19 children with other psychiatric disorders (Oppositional-defiant and Conduct Disorders, Dyslexia) and 27 healthy controls. Results showed a significant positive response to the anti-Yo antibody immunoreactivity in the Purkinje cells of the cerebellum of ADHD children, compared with the control group and the psychiatric non-ADHD children. This association points to an immune dysregulation and the involvement of the cerebellum in ADHD.