Abstracts and slides follow. Dr. Yolken, the organizer, opened the meeting by summarizing evidence suggesting that many cases of schizophrenia, and perhaps of bipolar disorder as well, may be caused by infectious agents. Dr. Torrey then provided an overview of epidemiological aspects of schizophrenia and bipolar disorder that are consistent with an infectious etiology in general and with toxoplasmosis and transmission by cats in particular. Several presentations focused specifically on Toxoplasma gondii . Dr. Barta discussed the history of the organism, its position in the evolution of parasites, and its life cycle and basic features.
Man is an intermediate host, and the cat species is the definitive host.
Dr. Carruthers described its mechanisms of cell invasion using various proteins and noted that the retinitis that sometimes follows congenital toxoplasma infection may not begin until adolescence. Behavioral effects of toxoplasmosis in the brain were described by several speakers. Dr. Holliman reviewed rodent studies that have demonstrated altered behavior in mice and rats infected with this parasite. Dr. Gilmore noted that in his study, humans with toxoplasma antibodies appear to have a modestly lower IQ, and Dr. Dickerson reported some preliminary results suggesting mild cognitive impairment associated with toxoplasma antibodies. Much discussion focused on the nature of cysts and their possible metabolic activity.