For the total sample, contacts with animals during pregnancy and age emerged as a non-significant predictors of TG IgG titers. Means of patients' and controls' TG IgG titers did not differ significantly but variances did; a subgroup of patients' titers reached much higher levels than those of controls. Patients in the high TG IgG subgroup were older (p=0.001), also they were older when psychiatric symptoms appeared, more individuals had regular animal contacts during pregnancy, or rural upbringing including regular animal contact, more consumption of raw meat, and a higher absolute treatment response (all trend levels). Regarding the short term course of patients, the investigators detected decreasing IgG titers in several individuals A power analysis demonstrated that results fell short of significance due to lack of statistical power. Based on the power analysis, the investigators propose an opel label, multicenter study at three regionally different sites within Germany (Halle, Hamm, Heidelberg). The investigators intent to study 173 first-episode patients with schizophrenia, schizoaffective, and schizophreniform disorder and 173 matched controls.