Sohye Kim

Maternal oxytocin response during mother–infant interaction: Associations with adult temperament

Oxytocin is a neuropeptide associated with social affiliation and maternal caregiving. However, its effects appear to be moderated by various contextual factors and stable individual characteristics. The purpose of this study was to investigate the relationship of self-reported state and trait measures (such as temperament, mood and affect) with peripheral oxytocin response in mothers. Fifty-five first-time mothers participated in a semi-structured procedure, during which time repeated peripheral oxytocin levels were measured before, during and after an episode of mother-infant interaction. The maternal oxytocin response was then calculated, based on the difference in oxytocin concentration between initial baseline and interaction phase. Mothers also completed state measures of positive and negative affect and depression, and trait measures of temperament, personality disturbance and depression across time. Regression analyses determined which factors were independently associated with maternal oxytocin response. The trait measure of adult temperament emerged as a significant predictor of oxytocin response. Two out of four Adult Temperament Questionnaire factor scales were independently associated with oxytocin response: Effortful Control was negatively associated, whereas Orienting Sensitivity was positively associated. No state measure significantly predicted oxytocin response. The results indicate that mothers who show an increased oxytocin response when interacting with their infants are more sensitive of moods, emotions and physical sensations; and less compulsive, schedule driven and task oriented. These findings link differences in individual temperament in new mothers with the peripheral oxytocin response, which may have implications in the pharmacologic treatment of disorders such as maternal neglect, post-partum depression and maternal addiction. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior.

Major Depression in Mothers Predicts Reduced Ventral Striatum Activation in Adolescent Female Offspring With and Without Depression

Prior research has identified reduced reward-related brain activation as a promising endophenotype for the early identification of adolescents with major depressive disorder (MDD). However, it is unclear whether reduced reward-related brain activation constitutes a true vulnerability for MDD. One way of studying vulnerability is through a high-risk design. Therefore, the aim of the current study was to determine whether reward-related activation of the ventral striatum is reduced in nondepressed daughters of mothers with a history of MDD (high-risk) similarly to currently depressed adolescent girls, compared with healthy controls. By directly comparing groups with a shared risk profile during differing states, we aimed to shed light on the endophenotypic nature of reduced reward processing for adolescent depression. We compared reward-related neural activity through functional magnetic resonance imaging (fMRI) between three groups of female biological offspring (N = 52) of mothers with differential MDD status: (a) currently depressed daughters of mothers with a history of MDD (MDD group; n = 14), (b) age- and socioeconomic status (SES)-matched never-depressed daughters of mothers with a history of MDD (high-risk group; n = 19), and (c) age- and SES-matched control daughters of mothers with no past or current psychopathology in either the mother or the daughter (healthy control group; n = 19). For the outcome phase of the reward task, right-sided ventral striatum activation was reduced for both currently depressed and high-risk girls compared with healthy controls. This ventral striatal activity correlated significantly with maternal depression scores. These findings provide further evidence of aberrant functioning for the United States Department of Health & Human Services, National Institutes of Health, National Institute of Mental Health (NIMH) Research Domain Criteria (RDoC)-defined domain of positive valence systems as a vulnerability factor for MDD and a potential endophenotype for the development of depression.

Maternal oxytocin response predicts mother-to-infant gaze.

The neuropeptide oxytocin is importantly implicated in the emergence and maintenance of maternal behavior that forms the basis of the mother-infant bond. However, no research has yet examined the specific association between maternal oxytocin and maternal gaze, a key modality through which the mother makes social contact and engages with her infant. Furthermore, prior oxytocin studies have assessed maternal engagement primarily during episodes free of infant distress, while maternal engagement during infant distress is considered to be uniquely relevant to the formation of secure mother-infant attachment. Two patterns of maternal gaze, maternal gaze toward and gaze shifts away from the infant, were micro-coded while 50 mothers interacted with their 7-month-old infants during a modified still-face procedure. Maternal oxytocin response was defined as a change from baseline in the mothers plasma oxytocin level following interaction with her infant. The mothers oxytocin response was positively associated with the duration of time her gaze was directed toward her infant, while negatively associated with the frequency with which her gaze shifted away from her infant. Importantly, mothers who showed low/average oxytocin response demonstrated a significant decrease in their infant gaze during periods of infant distress, while such change was not observed in mothers with high oxytocin response. The findings underscore the involvement of oxytocin in regulating the mothers responsive engagement with her infant, particularly in times when the infants need for access to the mother is greatest. This article is part of a Special Issue entitled Oxytocin and Social Behav.

Mothers' unresolved trauma blunts amygdala response to infant distress.

While the neurobiology of post-traumatic stress disorder has been extensively researched, much less attention has been paid to the neural mechanisms underlying more covert but pervasive types of trauma (e.g., those involving disrupted relationships and insecure attachment). Here, we report on a neurobiological study documenting that mothers’ attachment-related trauma, when unresolved, undermines her optimal brain response to her infant’s distress. We examined the amygdala blood oxygenation level-dependent response in 42 first-time mothers as they underwent functional magnetic resonance imaging scanning, viewing happy- and sad-face images of their own infant, along with those of a matched unknown infant. Whereas mothers with no trauma demonstrated greater amygdala responses to the sad faces of their own infant as compared to their happy faces, mothers who were classified as having unresolved trauma in the Adult Attachment Interview (Dynamic Maturational Model) displayed blunted amygdala responses when cued by their own infants’ sadness as compared to happiness. Unknown infant faces did not elicit differential amygdala responses between the mother groups. The blunting of the amygdala response in traumatized mothers is discussed as a neural indication of mothers’ possible disengagement from infant distress, which may be part of a process linking maternal unresolved trauma and disrupted maternal caregiving.

Oxytocin and postpartum depression: Delivering on what's known and what's not

The role of oxytocin in the treatment of postpartum depression has been a topic of growing interest. This subject carries important implications, given that postpartum depression can have detrimental effects on both the mother and her infant, with lifelong consequences for infant socioemotional and cognitive development. In recent years, oxytocin has received attention for its potential role in many neuropsychiatric conditions beyond its well-described functions in childbirth and lactation. In the present review, we present available data on the clinical characteristics and neuroendocrine foundations of postpartum depression. We outline current treatment modalities and their limitations, and proceed to evaluate the potential role of oxytocin in the treatment of postpartum depression. The aim of the present review is twofold: (a) to bring together evidence from animal and human research concerning the role of oxytocin in postpartum depression, and (b) to highlight areas that deserve further research in order to bring a fuller understanding of oxytocins therapeutic potential. This article is part of a Special Issue entitled Oxytocin and Social Behav.

Unresolved trauma in mothers: intergenerational effects and the role of reorganization

A mothers unresolved trauma may interfere with her ability to sensitively respond to her infant, thus affecting the development of attachment in her own child, and potentially contributing to the intergenerational transmission of trauma. One novel construct within the Dynamic Maturational Model of Attachment and Adaptation (DMM) coding of the Adult Attachment Interview (AAI) is “reorganization,” a process whereby speakers are actively changing their understanding of past and present experiences and moving toward attachment security. We conducted a study of mothers with unresolved trauma, exploring their own attachment classification, attachment outcomes of their children, and the potential effects of reorganization on child attachment. Forty-seven first-time mothers participated in the AAI during pregnancy, and returned with their child at 11 months to assess child attachment using the Strange Situation Procedure. Mothers with and without unresolved trauma were compared. We found that mothers with unresolved trauma had insecure attachment themselves and were more likely to have infants with insecure attachment. However, the one exception was that all of the mothers with unresolved trauma who were reorganizing toward secure attachment had infants with secure attachment. These preliminary findings suggest that mothers who are reorganizing may be able to more sensitively respond to their childs cues, contributing to the development of secure attachment. While our results need to be replicated in a larger cohort, this study is the first to explore the construct of reorganization and its potential relationship with child attachment. If confirmed in future studies, it may provide clinical insight into the intergenerational transmission of insecure attachment within the context of unresolved trauma.

Early adverse experience and substance addiction: dopamine, oxytocin, and glucocorticoid pathways

Substance addiction may follow a chronic, relapsing course and critically undermine the physical and psychological well‐being of the affected individual and the social units of which the individual is a member. Despite the public health burden associated with substance addiction, treatment options remain suboptimal, with relapses often seen. The present review synthesizes growing insights from animal and human research to shed light upon developmental and neurobiological pathways that may increase susceptibility to addiction. We examine the dopamine system, the oxytocin system, and the glucocorticoid system, as they are particularly relevant to substance addiction. Our aim is to delineate how early adverse experience may induce long‐lasting alterations in each of these systems at molecular, neuroendocrine, and behavioral levels and ultimately lead to heightened vulnerability to substance addiction. We further discuss how substance addiction in adulthood may increase the risk of suboptimal caregiving for the next generation, perpetuating the intergenerational cycle of early adverse experiences and addiction.

Oxytocin and Maternal Brain Plasticity

Although dramatic postnatal changes in maternal behavior have long been noted, we are only now beginning to understand the neurobiological mechanisms that support this transition. The present paper synthesizes growing insights from both animal and human research to provide an overview of the plasticity of the mothers brain, with a particular emphasis on the oxytocin system. We examine plasticity observed within the oxytocin system and discuss how these changes mediate an array of other adaptations observed within the maternal brain. We outline factors that affect the oxytocin-mediated plasticity of the maternal brain and review evidence linking disruptions in oxytocin functions to challenges in maternal adaptation. We conclude by suggesting a strategy for intervention with mothers who may be at risk for maladjustment during this transition to motherhood, while highlighting areas where further research is needed.

The mind in the making: Developmental and neurobiological origins of mentalizing.

Tracing the development of mentalizing is central to understanding how we come to learn about the mind. Barring significant biological or developmental abnormalities, we all come to form an understanding of the mind and mental states. But how does this happen, and what accounts for individual differences in abilities to reason about mental states (i.e., desires, feelings, intentions)? The first section of the present article brings together relevant developmental research to outline the normative developmental trajectory of mentalizing. The second section delves into attachment research to drive home the point that this fundamental human capacity develops in tandem with early attachment relationships, and underscores the fact that suboptimal attachment contexts can hinder the developmental progression of mentalizing. Biobehavioral mechanisms that have been proposed to mediate this developmental process are discussed in the third section, with a particular focus on the neuropeptide oxytocin.

Mothers with substance addictions show reduced reward responses when viewing their own infant's face

Maternal addiction constitutes a major public health problem affecting children, with high rates of abuse, neglect, and foster care placement. However, little is known about the ways in which substance addiction alters brain function related to maternal behavior. Prior studies have shown that infant face cues activate similar dopamine‐associated brain reward regions to substances of abuse. Here, we report on a functional MRI study documenting that mothers with addictions demonstrate reduced activation of reward regions when shown reward‐related cues of their own infants. Thirty‐six mothers receiving inpatient treatment for substance addiction were scanned at 6 months postpartum, while viewing happy and sad face images of their own infant compared to those of a matched unknown infant. When viewing happy face images of their own infant, mothers with addictions showed a striking pattern of decreased activation in dopamine‐ and oxytocin‐innervated brain regions, including the hypothalamus, ventral striatum, and ventromedial prefrontal cortex—regions in which increased activation has previously been observed in mothers without addictions. Our results are the first to demonstrate that mothers with addictions show reduced activation in key reward regions of the brain in response to their own infants face cues. Hum Brain Mapp 38:5421–5439, 2017.