Oxytocin as a transdiagnostic biomarker of well-being in severe mental illness during the Covid-19 pandemic

Individuals with severe mental illness (SMI) have been found to suffer a greater decline in psychological well-being compared to the general population in times of stress. The present study aimed to examine clinical and endocrine resilience factors of psychological well-being in SMI patients during the Covid-19 pandemic. After Covid-19 crisis outburst in Israel 112 participants, 69 outpatients, and 43 inpatients and day treatment patients were recruited. Outpatients signed an online informed consent and filled in questionnaires regarding their level of mental health symptoms (OQ-45), fear of Covid-19 (FCV), and psychological well-being (PWB). Inpatients answered the same questionnaires and in addition, went through a positive social interaction paradigm while providing three saliva samples to measure their s-IgA and oxytocin (OT) levels. A strong negative correlation was found in the whole sample between reported mental health symptoms, fear of Covid-19, and well-being. Hierarchical regression did not find additional contribution of the fear of the pandemic in predicting well-being beyond the impact of symptomatology. For inpatients (N = 39) only, hierarchical regression found that oxytocin, but not s-IgA could explain 5% of the variance of well-being (R = 0.05) in individuals with SMI regardless of their mental health symptoms (R = 0.46) and their marital status (R = 0.21). OT is suggested as a possible independent biological resilience factor of well-being in times of major stress among SMI patients. It is still unknown whether OT is a mediator that contributes to well-being or a biological marker that indicates the degree of beneficial social interactions.