Q. I am trying to find out the link(s) between the auto immune system and psychiatric disorders. Are there any diseases that are related to psychological disorders?

A. That's an intriguing question that has recently made the news, in relation to children developing obsessive-compulsive symptoms after a recent strep infection. First, though, let's define autoimmune disorders.

Basically, these are conditions in which the body attacks itself. That is, antibodies are produced that attack the body's own tissues, instead of some infectious organism, such as a virus or bacterium. A good example is systemic lupus erythematosus (lupus or SLE). This is a multi-organ disease, in which the body produces antibodies directed against the nucleus of its own cells, as well as against parts of neurons (brain cells).

It's thus not surprising that some patients with SLE will develop neuropsychiatric complications, such as mood changes or even psychosis. A similar mechanism--that is, antibodies directed against brain tissue--has been posited in a new group of conditions called PANDAS; that is, pediatric autoimmune neurological disorders associated with streptococcal infections.

The observation that some children will develop OCD-like symptoms during or after the course of strep infections has led to the hypothesis that antibodies aimed at the strep germs are somehow misdirected against specific parts of the child's brain. [See, e.g., Dinn et al, Int J Psychiatry Med 2001;31:311-20].

Many other connections have been found between autoimmune mechanisms and psychiatric symptoms; e.g., high rates of autoimmune thyroiditis in bipolar disorder patients (Kupka et al, Biol Psychiatry 2002 Feb 15;51(4):305-11) and some indication that individuals with schizophrenia have been exposed to viral infections in utero (this doesn't mean schizophrenia is an autoimmune disorder, but it does raise interesting questions about viral exposure).

I hope this gets you started!

July 2002

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