Adolescents' Hormonal Responses to Social Stress and Associations with Adolescent Social Anxiety and Maternal Comfort: A Preliminary Study.

Both social support and social stress can impact adolescent physiology including hormonal responses during the sensitive transition to adolescence. Social support from parents continues to play an important role in socioemotional development during adolescence. Sources of social support and stress may be particularly impactful for adolescents with social anxiety symptoms. The goal of the current study was to examine whether adolescent social anxiety symptoms and maternal comfort moderated adolescents' hormonal response to social stress and support. We evaluated 47 emotionally healthy 11- to 14-year-old adolescents' cortisol and oxytocin reactivity to social stress and support using a modified version of the Trier Social Stress Test for Adolescents that included a maternal comfort paradigm. Findings demonstrated that adolescents showed significant increases in cortisol and significant decreases in oxytocin following the social stress task. Subsequently, we found that adolescents showed significant decreases in cortisol and increases in oxytocin following the maternal comfort paradigm. Adolescents with greater social anxiety symptoms showed higher levels of cortisol at baseline but greater declines in cortisol response following maternal social support. Social anxiety symptoms were unrelated to oxytocin response to social stress or support. Our findings provide further evidence that mothers play a key role in adolescent regulation of physiological response, particularly if the stressor is consistent with adolescents' anxiety. More specifically, our findings suggest that adolescents with higher social anxiety symptoms show greater sensitivity to maternal social support following social stressors. Encouraging parents to continue to serve as a supportive presence during adolescent distress may be helpful for promoting stress recovery during the vulnerable transition to adolescence.

Mother-child neural synchronization is time linked to mother-child positive affective state matching.

In the first years of life, in which self-regulation occurs via external means, mother-child synchronization of positive affect (PA) facilitates regulation of child homeostatic systems. Mother-child affective synchrony may contribute to mother-child synchronization of neural systems, but limited research has explored this possibility. Participants were 41 healthy mother-child dyads (56% girls; Mage = 24.76 months; s.d. = 8.77 months, Range = 10-42 months). Mothers' and children's brain activities were assessed simultaneously using near-infrared spectroscopy while engaging in dyadic play. Mother and child PA during play were coded separately to characterize periods in which mothers and children (i) matched on high PA, (ii) matched on low/no PA or (iii) showed a mismatch in PA. Models evaluated moment-to-moment correlations between affective matching and neural synchrony in mother-child dyads. Greater positive affective synchrony, in which mother and child showed similarly high levels of PA but not similarly low levels of PA, was related to greater synchrony in medial and lateral frontal and temporoparietal regions. Age moderated associations between mother and child neural activities but only during moments of high PA state matching. Positive, synchronous mother-child interactions may foster greater neural responding in affective and social regions important for self-regulation and interpersonal bonds.

Postpartum Depression Is Associated With Altered Neural Connectivity Between Affective and Mentalizing Regions During Mother-Infant Interactions.

Although there has been growing interest in mood-related neural alterations in women in the initial weeks postpartum, recent work has demonstrated that postpartum depression often lingers for months or years following birth. However, research evaluating the impact of depression on maternal brain function during mother-infant interactions in the late postpartum period is lacking. The current study tested the hypothesis that depressive symptoms at 12-months postpartum are associated with neural alterations in affective and social neural regions, using near-infrared spectroscopy during in vivo mother-infant interactions. Participants were 23 birth mothers of 12-month-old infants (60% boys). While undergoing near-infrared spectroscopy, mothers engaged in an ecologically valid interactive task in which they looked at an age-appropriate book with their infants. Mothers also reported on their depressive symptoms in the past week and were rated on their observed levels of maternal sensitivity during mother-infant play. Greater depressive severity at 12-months postpartum was related to lower connectivity between the right temporoparietal junction and the lateral prefrontal cortex, but greater connectivity between the right temporoparietal junction and anterior medial prefrontal cortex during mother-infant interaction. Given the putative functions of these neural regions within the maternal brain network, our findings suggest that in the context of depression, postpartum mothers' mentalizing about her infants' thoughts and feelings may be related to lower ability to express and regulate her own emotions, but greater ability to engage in emotional bonding with her infant. Future work should explore how connectivity among these regions is associated with longitudinal changes in maternal behavior, especially in the context of changes in mothers' depressive symptoms (e.g., with treatment) over time.