Cytomegalovirus Exposure and IQ in Patients With Severe Mental Illness and Healthy Individuals

Cytomegalovirus (CMV) infection in immunocompetent adults is usually asymptomatic, but can result in lifelong infection. Infection occurring congenitally or in the context of immunodeficiency can lead to cognitive impairment. Due to the suggested immune system and blood-brain barrier disturbances in severe mental illness and the sex-dependent immune response to latent CMV, we hypothesized that CMV exposure is associated with lower intelligence quotient (IQ) among patients with schizophrenia spectrum (SZS) and bipolar spectrum disorders (BDS), but not healthy controls (HC), and that putative associations are sex-dependent.