The Role of Oxytocin in Early Life Adversity and Later Psychopathology: a Review of Preclinical and Clinical Studies

Purpose: Oxytocin is a peptide hormone integral in parturition and milk let-down, and is increasingly recognized as an important regulator of human social behaviors including bonding, trust, fear, and stress. There is an increasing evidence that oxytocin is intricately involved in a broad array of neurophysiological functions and may be a common system implicated in multiple psychiatric disorders. This review examines the putative role of oxytocin in early life adversity-mediated risk for later development of subtypes of psychiatric conditions. Several lines of evidence are reviewed including oxytocin levels, response to exogenous oxytocin administration, and genetic studies. Recent findings: To date, most studies report lower levels of peripheral and central oxytocin in a dose-response manner in adults exposed to early life adversity. Individuals exposed to early life adversity seem to have a differential response to exogenous oxytocin administration, sometimes with negative outcomes. Several polymorphisms in the oxytocin receptor and emerging epigenetic studies point to a link between oxytocinergic systems and psychiatric disorders. Summary: Specific limitations of the studies in the field are highlighted, and areas for future research are described. Considerably more research is needed to understand the complex role of the oxytocin system in early life adversity and its consequences.