Intracellular parasite Toxoplasma gondii is considered to be an infectious agent, which plays a role in the aetiology and pathogenesis of some cases of shizophrenia. TG infection-related cognitive dysfunction is considered as an element of vulnerability for the development of some schizophrenia subtypes.
The hypothesis that links TG infection and schizophrenia is supported above all by these findings: a) a statistically significant increase of antibody titres to TG in first-episode schizophrenia patients, b) a positive correlation of the antibodies to TG and psychopathology scores in first-episode schizophrenia, c) an increased level of cognitive abnormalities in schizophrenia patients with serologic evidence of TG infection compared to the patients without signs of TG infection, and d) cognitive and personality changes in TG infected non-schizophrenic subjects and behavioural changes in animal models. The objectives of the CNS project are to investigate TG infected and non-infected subgroups of outpatients with schizophrenia spectrum disorders - participants of the structured day-care programme with respect to 1) the differences in their symptom severity and cognitive performance, 2) the development of a different cognitive profile in the course of one year follow-up, and 3) a different capacity to participate in and benefit from a structured day-care programme for schizophrenia spectrum disorders.
Clinical implications of the CNS project could be a replication of previous studies of postnatal latent toxoplasmosis as a disease-modifying factor in schizophrenia, resulting in more assertive preventive measures, more appropriate cognitive rehabilitation of TG infected schizophrenia patients and more inclusion of TG antibodies in screening batteries of high-risk schizophrenia population.