Depressed Mothers and Oxytocin

oxytocinOxytocin is often brought up in conversations about childbirth. After childbirth, new mothers normally experience surges of oxytocin that increase feelings of maternal bonding, trust, and empathy. In addition to facilitating pair bonding, recent studies have shown oxytocin  plays a greater role in mental health than originally thought. Low levels of oxytocin may be a phenomenon linked to depression.

Maternal depression across the postbirth period has long-term negative consequences for infant development. Little is known of the neurobiological underpinnings, but they could involve oxytocin, a neuropeptide that is dysfunctional in depression and is implicated in birth and parenting.

The authors recruited a community cohort of women with high or low depression scores 2 days after childbirth and measured depression again at 6 and 9 months. When the child was 6, the authors evaluated the families of 46 chronically depressed mothers and 103 mothers reporting no depression since childbirth. The child was assessed for psychiatric diagnoses, social engagement, and empathy. Mother, father, and child were tested for salivary oxytocin level and variation in the rs2254298 single nucleotide polymorphism on the OXTR gene.

Of the children of the chronically depressed mothers, 61% displayed axis I disorders, mainly anxiety and oppositional defiant disorder, compared with 15% of the children of nondepressed mothers. In the depressed mothers’ families, salivary oxytocin was lower in mothers, fathers, and children. These children also had lower empathy and social engagement levels.

In addition, the rs2254298 GG homozygous genotype was overrepresented in depressed mothers and their families, which correlated with lower salivary oxytocin. Presence of a single rs2254298 A allele (GA or AA genotype) in depressed mothers markedly decreased risk of child psychopathology.

The negative effect of chronic maternal depression on child social outcomes was related to genetic and peripheral biomarkers of the oxytocin system. This suggests a potential for oxytocin-based interventions in depression treatment.

Impact of Maternal Depression Across the First 6 Years of Life on the Child’s Mental Health, Social Engagement, and Empathy: The Moderating Role of Oxytocin. Yael Apter-Levy, M.A.; Michal Feldman, M.A.; Adam Vakart, M.A.; Richard P. Ebstein, Ph.D.; Ruth Feldman, Ph.D. Am J Psychiatry 2013;:. 10.1176/appi.ajp.2013.12121597