I believe I’ve recognized an error in the Straight Dope article “If cat poop is so toxic to pregnant women, why aren’t there more birth defects? Can cat poop cause schizophrenia?”, at http://www.straightdope.com/columns/read/2637/if-cat-poop-is-so-toxic-to-pregnant-women-why-arent-there-more-birth-defects
Specifically, the article states:
“But get this. Forty-five percent of schizophrenics tested positive in one study for both T. gondii and D-lysergic acid diethylamide, better known as LSD. To quote a recent paper: “These results support the hypothesis that T. gondii may cause schizophrenia and may do so by producing or triggering the production of an hallucinogenic chemical”
A word of caution: our authors’ impressive theoretical edifice is built on some pretty thin evidence. It’s simplistic to say T. gondii works by triggering the production of LSD–among other problems with the idea, acid mainly gives rise to visual hallucinations, whereas the delusions of schizophrenics are primarily auditory (e.g., hearing voices).”
Now, I can see how the mistake was made, and it was a reasonable reading of the article cited if you aren’t familiar with the chemistry/techniques, but what the cited article actually said was that the analyte in question showed the same response in fish chromatophores as LSD. This is not to say that LSD was present- the test is incapable of determining that. This is the same as, say, using a dog that you know chases its tail if you give him LSD and then giving him Substance x. If he chases his tail, that’s a positive result, but it doesn’t mean substance x is LSD or even anything similar to it.
Basically, the error was in presuming the following passage in the cited article referred to a test that determined a match in chemical structure/identity rather than a corelation in biological response.
I notice a number of websites/discussion boards have been linking to this article and discussing it, so it would perhaps be appropriate to correct the article to prevent further confusion.
The section of the cited article from which the mistake likely originates:
" In one set of studies,Toxoplasma-infected schizophrenics
tested positive for D-lysergic acid diethylamide (LSD) using a fish chromato-
phore bioassay (Silverman and Varela 1958;Varela,Vázquez, and Torroella 1956).
After showing that the peritoneal fluid of T. gondii infected mice tested positive,
the researchers found that 44.9 percent of schizophrenics tested positive for both
T. gondii and LSD, whereas none of the non-schizophrenic controls tested posi-
tive for LSD" page 331 of Ledgerwood LG, Ewald PW, Cochran GM. Genes, germs, and schizophrenia: an evolutionary perspective. Perspect Biol Med 2003;46:317–48