Epigenetic Regulation of the Oxytocin System: Adaptation to Overcontrolling Parenting, and Links to Relationships and Internalizing Symptoms

DNA methylation of the oxytocin receptor gene (OXTRm) reduces the gene’s expression and has been associated with a variety of environmental precursors and outcomes for social development and mental health, both favorable and detrimental. This multi-method, longitudinal study, using a diverse community sample of 184 adolescents followed from age 13 to 28, examined the links between OXTRm and the experience of overcontrolling parenting in adolescence and conflict with romantic partners and internalizing symptoms in adulthood. Female, but not male, adolescents who experienced overcontrolling parenting at age 13 in the form of psychological control had lower levels of OXTRm at age 28. Reduced OXTRm was associated with greater relationship conflict at age 27, as reported by their romantic partner, and reduced sensitivity to the conflict, lending support to the theory that greater oxytocin reduces the salience of negative stimuli, such as angry and fearful faces. Finally, lower levels of OXTRm were associated with fewer internalizing symptoms at ages 24-25, which is also consistent with oxytocin reducing the salience of negative stimuli and lends support to the positive association between OXTRm and internalizing symptoms, particularly depression and anxiety, in the literature. Findings are consistent with the “tend-and-befriend” hypothesis which states that social stress leads to increased oxytocin, which spurs individuals to seek social support and reduce stress. Overall, these results suggest that lower OXTRm, and therefore a greater ability to take in oxytocin, is not necessarily the “favorable” state in all cases, as it is linked to diverse developmental, social, and mental health correlates.