In the psychiatric domain, infectious agents may produce some surprises.
For instance, evidence has been building since the late 1980s that the
streptococcus bacterium might cause, or at least contribute to, certain cases
of obsessive-compulsive disorder (OCD). And now a new study out of London
bolsters that argument.
Isobel Heyman, M.D., Ph.D., a consulting child and adolescent psychiatrist
at the Institute of Psychiatry in London, and coworkers drew blood from 50
children and adolescents with DSM-IV-defined OCD, 100 children and
adolescents with other conditions (stroke, metabolic movement disorders, or
encephalitis), and 40 healthy children and adolescents.
They then determined whether antibodies in the blood samples reacted with a
specific antigen—delipidated human basal ganglia (caudate and
putamen)—since the basal ganglia has been heavily implicated in OCD.
They found anti-basal ganglia antibodies in 42 percent of subjects with
OCD, but only in 2 percent to 10 percent of the control groups—a highly
These results, Heyman and her group concluded in the October British
Journal of Psychiatry, thus suggest that "central nervous system
autoimmunity may have a role in a significant subgroup of cases of OCD."
They also imply that the autoimmunity is provoked by the strep bacterium since
patients with a neurological disorder robustly established as a post-strep
autoimmune disorder—Sydenham's chorea—usually test positive for
antibodies that attack basal ganglia.
The findings are too preliminary to have immediate practical implications
for clinicians, Heyman told Psychiatric News. "Children and
adolescents with OCD should receive the current evidence-based treatments,
which are cognitive-behavior therapy with or without SSRI
However, she added, "It will be important to research whether
children with OCD who have evidence of previous strep infection respond any
differently to these standard treatments. Our current clinical view is that
they respond in the same way, with up to 80 percent of children showing a good
response to treatment."
Also, "if it is proven that recurrent strep infections are associated
with OCD in vulnerable individuals, and strep is isolated in these children,
it might be reasonable," she said, "to study further whether
maintenance on antibiotics reduces infectious episodes and in turn is
associated with an improvement in OCD. But we are a long way from this being
standard clinical practice, as it needs further trials."
The study was funded by Action Research UK, the Barnwood House Trust, and
the University College London.
An abstract of "Incidence of Anti-Brain Antibodies in Children
With Obsessive-Compulsive Disorder" is posted at<http://bjp.rcpsych.org/cgi/content/abstract/187/4/314>.▪
Br J Psychiatry2005187314