Antibodies to infectious agents and the positive symptom dimension of subclinical psychosis: The TRAILS study

Infections have been suggested to play a role in the etiology of schizophrenia, but the evidence for this has been inconsistent. Schizophrenia patients have an increased risk of infections as a result of hospitalizations or life style factors. Therefore a study on early subclinical manifestations of psychosis in relation to virus infections is warranted. We examined whether serum antibodies against human Herpes viruses and Toxoplasma gondii were associated with subclinical symptoms of psychosis in adolescents. Data were collected as part of the TRacking Adolescents' Individual Lives Survey (TRAILS) cohort, a large prospective cohort of Dutch adolescents. A total of 1176 participants with an available Community Assessment of Psychic Experiences (CAPE) and an available blood sample were included in this analysis. Solid-enzyme immunoassay methods were used to measure the presence of immunoglobulin G (IgG) antibodies in serum to the Herpes virus family and to T. gondii. There was no significant association between serologic evidence of infection with human Herpes viruses or T. gondii and the risk of subclinical positive experience of psychosis. Subjects with a positive serological reaction to Epstein-Barr Virus (EBV) had higher scores on the positive dimension of psychosis measured by CAPE (b = 0.03, P = 0.02). This significant association was observed in males, but not in females. The current study suggests that there is no significant association between serological evidence of infection to human Herpes viruses and positive subclinical experience of psychosis, whereas there was an association between EBV infection and subclinical psychotic symptoms in boys.