Non-SARS Coronaviruses in Individuals with Psychiatric Disorders.

BACKGROUND: The pandemic caused by severe acute respiratory syndrome-Coronavirus-2 (SARS-CoV-2) has highlighted the importance of coronaviruses in human health. Several seasonal, non-SARS Coronaviruses are endemic in most areas of the world. In a previous study, we found that the level of antibodies to these seasonal Coronaviruses was elevated in persons with a recent onset of psychosis. In the current study, the level of antibodies to seasonal Coronaviruses was compared between individuals with psychiatric disorders and a non-psychiatric comparison group.

METHODS: Participants (N = 195) were persons with a diagnosis of schizophrenia, bipolar disorder, major depressive disorder, or without a psychiatric disorder. Each participant had a blood sample drawn from which were measured IgG antibodies to the spike proteins in four non-SARS Coronaviruses, 229E, HKU1, NL63, and OC43, using a multiplex electrochemiluminescence assay. Linear regression models were employed to compare the levels of antibodies between each psychiatric group and the comparison group adjusting for demographic variables. Logistic regression models were employed to calculate the odds ratios associated with increased levels of antibodies to each seasonal Coronavirus based on the 50th percentile level of the comparison group.

RESULTS: The schizophrenia group had significantly increased levels of antibodies to the seasonal Coronaviruses OC43 and NL63. This group also had increased odds of having elevated antibody levels to OC43. The major depression group showed a significantly lower level of antibodies to Coronavirus 229E. There were no significant differences between any of the psychiatric groups and the comparison group in the levels of antibodies to seasonal Coronaviruses 229E or HKU1.

CONCLUSIONS: The elevated level of antibodies to OC43 and NL63 in the schizophrenia group indicates increased exposure to these agents and raises the possibility that Coronaviruses may contribute to the etiopathology of this disorder. The cause-and-effect relationship between seasonal Coronaviruses and psychiatric disorders should be the subject of additional investigations focusing on longitudinal cohort studies.