Mothers with substance addictions show reduced reward response to their own infants: Can intranasal oxytocin be a novel treatment?

• In Event: Perinatal Substance Use affects the Neural Basis of Mother-Infant Attachment

Abstract

Maternal substance addiction constitutes a major public health problem affecting more than 150,000 children each year, with high rates of child abuse and neglect reported in affected families. Unlike many mothers who find engaging with their own infants to be a uniquely rewarding experience, mothers with addictions may be less able to respond appropriately to their infants’ cues, finding them less intrinsically rewarding and more stress-provoking. Despite the reported difficulties, little is known about the ways in which substance addiction alters brain function underlying maternal behavior. Prior neuroimaging studies have shown that infant cues and substances of abuse similarly activate dopaminergically innervated brain reward circuits, suggesting the possibility that substances may co-opt the brain circuitry critical for maternal caregiving. Here, we report on a functional magnetic resonance imaging (fMRI) study documenting that mothers with addictions demonstrate reduced activation of reward regions when shown cues of their own infants. We further report on preliminary data suggesting that intranasal oxytocin may be effective in reversing the disrupted maternal brain responses in these mothers.

Thirty-six mothers seeking treatment at an inpatient substance abuse facility underwent fMRI scanning at 6 months postpartum, while viewing happy and sad face images of their own infant, along with those of a matched unknown infant. Effects of intranasal oxytocin were examined as part of a randomized double-blinded crossover study, involving a subsample of 3 addicted mothers and an independent sample of 10 non-addicted mothers, who were given a nasal spray of oxytocin or placebo prior to one of two fMRI scanning sessions.

When viewing happy face images of their own infant compared to those of an unknown infant, mothers with addictions showed a striking pattern of decreased activation in dopamine- and oxytocin-innervated brain reward regions, including the hypothalamus, ventral striatum, and ventromedial prefrontal cortex—regions in which increased activation has been observed in non-addicted mothers (Figure 1, panels A and B). Intranasal oxytocin, compared to placebo, was found to enhance activation in these brain reward regions, especially in mothers with addictions (Figure 1, panels C and D).

Our results are the first to delineate neurobiological correlates of disrupted mothering in mothers with addictions. The data suggest that mothers with substance addictions, even during intermittent periods of sobriety, demonstrate markedly reduced response to naturally rewarding cues from their infants. The deactivations observed here may help to explain the link between maternal substance use and impaired maternal caregiving. Intranasal oxytocin may have the potential to improve altered brain reward responses in these mothers, and may prove useful as a novel treatment in this population.

Authors

• Sohye Kim, University of Massachusetts Medical School
  Presenting Author

• Lane Strathearn, University of Iowa
  Non-Presenting Author