Wednesday, February 20, 2013
Toxoplasmosis and schizophrenia
Psychiatrist Hunts for Evidence Of Infection Theory of Schizophrenia
The theory that psychotic disorders are caused by infection went for decades without receiving more than an occasional raised eyebrow from researchers, but new studies have revived interest in its validity. If the theory turns out to be correct, psychiatry could begin to find cures in antimicrobials.
The prime suspect is Toxoplasma gondii, a protozoan parasite carried primarily by cats.
“When we started, it was considered a crazy idea,” psychiatrist E. Fuller Torrey, M.D., executive director of the Stanley Medical Research Institute (SMRI), told Psychiatric News. In the early 1970s, Torrey began to suspect an infectious origin of schizophrenia. He has been on this trail for decades.
Another piece of the evidence puzzle is that T. gondii can manufacture dopamine. “We know toxoplasma has the genes to produce a precursor of dopamine,” said Torrey. Excess dopamine in the brain has long been associated with psychosis. “This idea that excess dopamine [in schizophrenia] may be coming from an outside organism is kind of mind-blowing,” he said, marveling at the “smart little organism.”
We will talk more about Toxoplasmosis and Schizophrenia next class.