It takes two! Exploring sex differences in parenting neurobiology and behaviour

The interplay of oxytocin and sex hormones

The neuropeptide oxytocin has historically been associated with reproduction and maternal behavior. However, more recent research has uncovered that oxytocin has a much wider range of roles in physiology and behavior. Despite the excitement surrounding potential therapeutical applications of intranasally administered oxytocin, the results of these intervention studies have been inconsistent. Various reasons for these mixed results have been proposed, which tend to focus on methodological issues, such as study design. While methodological issues are certainly important, emerging evidence suggests that the interaction between oxytocin and sex hormones may also account for these varied findings. To better understand the purpose and function of the interaction of oxytocin with sex hormones, with a focus on estrogens, progesterone, and testosterone, we conducted a comprehensive thematic review via four perspectives: evolutionary, developmental, mechanistic, and survival. Altogether, this synergistic approach highlights the critical function of sex hormone activity for accomplishing the diverse roles of oxytocin via the modulation of oxytocin release and oxytocin receptor activity, which is also likely to contribute to the heterogeneity of outcomes after oxytocin administration.

Impact of parenthood on eating pathology in young adults

OBJECTIVE

Few studies investigated parenthood as a predictor of eating pathology in young adulthood. We studied the association between parenthood, in the first year after becoming a parent and beyond, and eating pathology. Furthermore, we examined whether moving in together with a partner affected this association.

METHOD

This study used data of four measurement waves from TRAILS (Tracking Adolescents' Individual Lives Survey), a Dutch community cohort study (N = 2229) from preadolescence into young adulthood. The Eating Disorder Diagnostic Scale (EDDS), a measure to assess eating pathology, was assessed at ages 22, 26, and 29. Risk for eating disorder was assessed at age 19. Pregnant participants were excluded.

RESULTS

Parenthood was not associated with an increase of eating pathology in the first year after becoming a parent and beyond. Instead, parents were more likely to report being free from eating pathology symptoms compared to childless individuals (OR 2.07, 95% CI: 1.11-3.84). Among those who reported experiencing at least one eating problem, parenthood was not associated with the number of eating problems. Moving in together with a partner did not alter the association between parenthood and eating problems and neither did this association differ between males and females.

DISCUSSION

Parenthood in young adulthood was associated with a decreased risk of having eating pathology.

PUBLIC SIGNIFICANCE STATEMENT

In this longitudinal study among young adults, parenthood was not associated with the development of eating pathology.

Do Parental Hormone Levels Synchronize During the Prenatal and Postpartum Periods? A Systematic Review

Physiological synchrony is the phenomenon of linked physiological processes among two or more individuals. Evidence of linkage between dyads has been found among a broad range of physiological indices, including the endocrine systems. During the transition to parenthood, both men and women undergo hormonal changes that facilitate parenting behavior. The present review sought to address the question as to whether hormonal synchronization occurs among expecting or new parents. A systematic literature search yielded 13 eligible records. The evidence of cortisol synchrony during the prenatal period, with additional testosterone, prolactin, and progesterone covariations in the time leading up to childbirth, was found to be most significant. During the postpartum period, parental synchrony was reported for oxytocin, testosterone, and cortisol levels. The implications of these covariations were found to translate into adaptive parenting behaviors and the facilitation of romantic bond. Associations with infant development were also reported, suggesting far-reaching effects of hormonal synchrony outside the parental dyad. The results highlight the importance of physiological interrelatedness during this sensitive period, underscoring the need for further research in this field. In view of the limited data available in this research domain, we have put forward a framework for future studies, recommending the adoption of standardized research protocols and repeated collections of specimens.

Mothers and fathers show different neural synchrony with their children during shared experiences

Parent-child shared experiences has an important influence on social development in children although contributions of mothers and fathers may differ. Neural synchronicity occurs between mothers and fathers and their children during social interactions but it is unclear whether they differ in this respect. We used data from simultaneous fNIRS hyperscanning in mothers (n = 33) and fathers (n = 29) and their children (3-4 years) to determine different patterns and strengths of neural synchronization in the frontal cortex during co-viewing of videos or free-play. Mothers showed greater synchrony with child than fathers during passive viewing of videos and the synchronization was positively associated with video complexity and negatively associated with parental stress. During play interactions, mothers showed more controlling behaviors over their child and greater evidence for joint gaze and joint imitation play with child whereas fathers spent more time gazing at other things. In addition, different aspects of child communication promoted neural synchrony between mothers and fathers and child during active play interactions. Overall, our findings indicate greater neural and behavioral synchrony between mothers than fathers and young children during passive or active shared experiences, although for both it was weakened by parental distress and child difficulty.

Skin-to-Skin Care and Spontaneous Touch by Fathers in Full-Term Infants: A Systematic Review

A series of studies have shown that mothers' early tactile behaviors have positive effects, both on full-term and preterm infants, and on mothers alike. Regarding fathers, research has focused mostly on paternal skin-to-skin care with preterm infants and has overlooked the tactile behavior effects with full-term newborns on infants' outcomes and on fathers themselves. The current systematic review considered the evidence regarding paternal tactile behaviors with full-term infants, including skin-to-skin care (SSC) and spontaneous touch (ST), during parent-infant interactions, and differentiated biophysiological, behavioral and psychological variables both in fathers and in infants. We also compared fathers' and mothers' tactile behaviors for potential differences. The few available studies suggest that paternal touch-SSC and ST-can have positive effects on fathers and infants alike. They also show that, despite some intrinsic differences, paternal touch is as pleasant as maternal touch. However, given the paucity of studies on the topic, we discuss why this field of research should be further explored.

The Current Concept of Paternal Bonding: A Systematic Scoping Review

Bonding is crucial to perinatal mental health. Despite an extensive body of literature on maternal bonding, few studies have focused on paternal bonding. This scoping review aimed to clarify the current state of the concept of paternal-infant/fetus bonding. The eligibility criteria were drawn from the population concept and context elements to answer the following questions: "what is paternal bonding?" and "what are the constructs of the concept of paternal bonding?" The review comprised 39 studies. Paternal bonding was associated with both positive and negative paternal behavior and thought and may be determined based on fathers' beliefs and rearing history. Most studies showed that father-child interaction is one of the factors promoting paternal bonding. However, fathers generally felt more distant from their babies post-delivery than mothers. Only a few studies originally defined paternal bonding; most relied on the definitions of maternal bonding. We found different descriptions lacking consensus. Few studies examined the differences between paternal and maternal bonding. No consensus exists on the concept, constructs, and assessment of paternal bonding. The causal relationship between paternal bonding and other variables is unexplored. Future studies should explore fathers' perspectives and experiences, focusing on the unknown aspects of paternal bonding identified in this review.

The resilient process of the family after diagnosis of childhood chronic illness: a qualitative meta-synthesis

PROBLEM

Childhood chronic illness has a serious effect on the whole family. As there is yet little known about how the families adjust to the diagnosis of childhood chronic illness, this qualitative meta-synthesis aims to further our knowledge regarding the resilient process.

ELIGIBILITY CRITERIA

A meta-synthesis review was conducted to explore the resilient process of the family after diagnosis of childhood chronic illness using nine electronic databases PubMed (MEDLINE), Web of Science, the Cochrane Library, SCOPUS, PsycINFO, CINAHL, Wan Fang, CBM, and CNKI from each database's inception to December 31,2020. Snowball sampling and manual search were performed to identify other relevant studies.

SAMPLE

Seventeen qualitative studies met the inclusion criteria and were analyzed into meta-synthesis.

RESULTS

Three key meta-themes were identified across the studies: (a) disintegration and vulnerability: emotional fluctuation and household chaos; (b) adjustment and adaptation: struggle with family needs; (c) recovery and reconstruction: growth and expectation.

CONCLUSION

Family adjustment to childhood chronic illness presents a complex, multifaceted and dynamic process. Identifying characteristics of family processes provides some practical interventions for families with a chronically ill child.

IMPLICATIONS

There is a need for all health professionals and social care services to be aware of the experience of family adjustment of children diagnosed with chronic illness. The specific intervention targeted at different periods of the family adjustment process is warranted to help families to recover from crises and deal better with challenges.

First-time fathers show longitudinal gray matter cortical volume reductions: evidence from two international samples

Emerging evidence points to the transition to parenthood as a critical window for adult neural plasticity. Studying fathers offers a unique opportunity to explore how parenting experience can shape the human brain when pregnancy is not directly experienced. Yet very few studies have examined the neuroanatomic adaptations of men transitioning into fatherhood. The present study reports on an international collaboration between two laboratories, one in Spain and the other in California (United States), that have prospectively collected structural neuroimaging data in 20 expectant fathers before and after the birth of their first child. The Spanish sample also included a control group of 17 childless men. We tested whether the transition into fatherhood entailed anatomical changes in brain cortical volume, thickness, and area, and subcortical volumes. We found overlapping trends of cortical volume reductions within the default mode network and visual networks and preservation of subcortical structures across both samples of first-time fathers, which persisted after controlling for fathers' and children's age at the postnatal scan. This study provides convergent evidence for cortical structural changes in fathers, supporting the possibility that the transition to fatherhood may represent a meaningful window of experience-induced structural neuroplasticity in males.

Autonomic cardiac profile in male and female healthcare professionals with and without preschoolers: differences evidenced by heart rate variability analysis

A reduced nocturnal cardiac vagal modulation has been observed in working women with preschoolers. Whether this adaptation also occurs in men remains an open question. The aim of this study was to analyze the cardiac autonomic profile of two groups of healthcare male professionals, one with and one without preschoolers, to be compared to females. Twenty-five working men with preschoolers (M_KID, age 35.41 ± 4.01 years) and 25 without (M_NOKID, 34.48 ± 6.00 years) were compared with 25 working women with preschoolers (W_KID, 37.7 ± 5.6 years) and 25 without (W_NOKID, 35.4 ± 7.2 years). A 24-h Holter electrocardiogram was performed for time and frequency domain analysis of the beat-to-beat variations of RR interval (RR) variability, during daytime (DAY) and nighttime (NIGHT). The power of RR variability in the high frequency band (HF_RR) was considered as an index of cardiac vagal modulation. RR variability indices were similar in M_KID and M_NOKID during both DAY and NIGHT. In contrast, W_KID showed a reduced nocturnal HF_RR compared to W_NOKID. The comparison of working men with and without preschoolers revealed no differences in the cardiac autonomic profile, in contrast with women. This suggests that sex and/or gender may represent a crucial factor in the cardiac neural control in the parental condition.

Exploring the role of endocrine factors in sensitive parenting in men

Parental sensitivity has been studied extensively in parenting research. Recently, there has been increasing attention to endocrine factors that may be related to parental sensitivity, such as oxytocin, vasopressin, testosterone, and cortisol. Although hormones do not act in isolation, few studies integrated multiple hormones and examined their combined associations with parental sensitivity. The current study aimed to explore the hormonal correlates of paternal sensitivity by examining in 79 first-time fathers of young infants (2-4 months old) (1) the separate and combined associations of basal oxytocin, vasopressin, testosterone, and cortisol levels with sensitivity, and (2) the associations between paternal sensitivity and oxytocin, vasopressin, testosterone, and cortisol reactivity following father-infant interactions. We additionally explored whether interactions between the various basal hormone levels could predict paternal sensitivity. Saliva for the quantification of fathers' hormone levels was sampled before and after an interaction with their infant to determine basal levels and reactivity. Results revealed no significant associations between sensitivity and basal hormone levels or reactivity. However, results indicated that cortisol and testosterone interacted in their effects on paternal sensitive parenting. Namely, fathers with low basal cortisol levels showed more sensitivity with increasing T levels, but fathers with high cortisol levels were less sensitive with increasing T levels. However, it should be noted that the latter slope was not significantly different from zero. These findings suggest that variations in parental sensitivity might be better explained by interactions between hormones than by single hormone levels.

The Role of Paternal Involvement on Behavioral Sensitive Responses and Neurobiological Activations in Fathers: A Systematic Review

As fathering research has flourished, a growing body of studies has focused on behavioral and neurobiological mechanisms, respectively associated with caregiving sensitivity and responsiveness to infant stimuli. However, the association between these aspects and the key concept of paternal involvement in childcare (i.e., contribution in infant care in terms of time, availability, and responsibility) has been poorly investigated. The current work aims to systematically review the role of involvement in childcare on both neural activations and sensitive behaviors in fathers by examining (a) how paternal involvement has been measured and (b) whether paternal involvement has been associated with neurobiological activation and behavioral sensitive responses. Inclusion criteria were peer-reviewed quantitative studies, concerning fathers responding to infant stimuli at neurobiological or behavioral level, and including a quantitative measurement of paternal involvement in childcare. A quality rating for each study has been performed based on the measurements adopted to assess paternal involvement. Of 2,529 articles, 27 studies were included. According to our quality rating, 10 out of 27 studies included fairly good-standard measures for measuring paternal involvement, whereas 17 studies used good-standard measures. In addition, 11 studies provided details of paternal involvement in the context of neurobiological responses to infant stimuli, whereas 16 addressed paternal sensitive behaviors. Overall, only 8 studies reported relevant findings about the relationship between paternal involvement and neurobiological responses or sensitive behaviors in fathers. The present study is the first systematically evaluating the scope of paternal involvement in the field of Paternal Brain and fathers' sensitive responsiveness research. When high-standard measures are used, paternal involvement seems to play a significant role in modulating both the hormonal and the neural pathways associated with paternal behaviors. Remarkably, the role of paternal engagement may underpin an adaptive nurturance that is not dependent on pregnancy and childbirth but on caregiving experience. A promising positive link between paternal involvement and behavioral sensitivity may be expected in further studies, which will need to corroborate our conclusion by adopting detailed and appropriate measures assessing paternal involvement. As a future line of research, the inclusion of gay fathers may be beneficial for the field.

Neurobiological Correlates of Fatherhood During the Postpartum Period: A Scoping Review

During the postpartum period, the paternal brain suffers extensive and complex neurobiological alterations, through the experience of father-infant interactions. Although the impact of such experience in the mother has been increasingly studied over the past years, less is known about the neurobiological correlates of fatherhood-that is, the alterations in the brain and other physiological systems associated with the experience of fatherhood. With the present study, we aimed to perform a scoping review of the available literature on the genetic, neuroendocrine, and brain correlates of fatherhood and identify the main gaps in the current knowledge. PubMed, Scopus, and Web of Science electronic databases were searched for eligible studies on paternal neuroplasticity during the postpartum period, over the past 15 years. Reference lists of relevant key studies and reviews were also hand-searched. The research team independently screened the identified studies based on the established inclusion criteria. Extracted data were analyzed using tables and descriptive synthesis. Among the 29 studies that met our inclusion criteria, the vast majority pertained to neuroendocrine correlates of fatherhood (n = 19), followed by brain activity or connectivity (n = 7), association studies of candidate genes (n = 2), and brain structure correlates (n = 1). Collectively, studies published during the past 15 years suggest the existence of significant endocrine (testosterone, oxytocin, prolactin, and cortisol levels) and neurofunctional alterations (changed activity in several brain networks related to empathy and approach motivation, emotional processing and mentalizing, emotion regulation, dorsal attention, and default mode networks) as a result of fatherhood, as well as preliminary evidence of genetic variability accounting for individual differences during the postpartum period in fathers. No studies were so far published evaluating epigenetic mechanisms associated with the paternal brain, something that was also the focus of the current review. We highlight the need for further research that examines neuroplasticity during the experience of fatherhood and that considers both the interplay between hormones and simultaneous assessment of the different biomarkers (e.g., associations between hormones and neural activity); data collection protocols and assessment times should also be refined.

Early Life Adversity and Males: Biology, Behavior, and Implications for Fathers' Parenting

Fathers have an important and unique influence on child development, but influences on fathers' parenting have been vastly understudied in the scientific literature. In particular, very little empirical research exists on the effects of early life adversity (ELA; e.g. childhood maltreatment, parental separation) on later parenting among fathers. In this review, we draw from both the human and non-human animal literature to examine the effects of ELA, specifically among males, in the following areas: 1) neurobiology and neurocognitive functioning, 2) hormones and hormone receptors, 3) gene-environment interactions and epigenetics, and 4) behavior and development. Based on these findings, we present a conceptual model to describe the biological and behavioral pathways through which exposure to ELA may influence parenting among males, with a goal of guiding future research and intervention development in this area. Empirical studies are needed to improve understanding of the relationship between ELA and father's parenting, inform the development of paternal and biparental interventions, and prevent intergenerational transmission of ELA.

The roots of paternal depression: Experienced and nonexperienced trauma or Folie a Deux?

The transition to fatherhood may be challenged with anxiety and trepidation. A high prevalence has been found for paternal depression and it is reactive to maternal depression. This review aims to address potential sources of paternal depression, which may have adverse consequences on child development. We describe through three hypotheses how fathers may be at risk of depression during the transition to fatherhood: (1) psychological (interacting with ecological systems); (2) brain functional∖structural changes; and (3) (epi)genomic. We propose that paternal stressful experiences during the transition to fatherhood may be the source for paternal depression through direct stressful paternal experiences or via (potential, currently debated) nonexperienced (by the father) epigenomic transgenerational transmission. On the other hand, we suggest that resilient fathers may undergo a transient dysphoric period affected by identifying with the newborn's vulnerability as well as with the mother's postpartum vulnerability resulting in "paternity blues." In accordance with recent views on paternal "heightened sensitivity" toward the infant, we propose that the identification of both parents with the vulnerability of the newborn creates a sensitive period of Folie a Deux (shared madness) which may be a healthy transient, albeit a quasi-pathological period, recruited by the orienting response of the newborn for survival.

Parenting and addictions: Current insights from human neuroscience

Purpose

A growing body of human research has documented associations between the maternal brain and maternal substance use and addictions. This neuroscience-informed approach affords the opportunity to unpack potential neurobiological mechanisms that may underscore challenges in maternal caregiving behavior among mothers with addictions and provide new directions for parenting interventions.

Findings

Consistent with theoretical models of parenting and addictions, five studies evidence both hypo- and hyper-reactivity to infant affective cues across neuroimaging methods and tasks that incorporate both infant face and cry stimuli. Three structural and resting-state brain studies as a function of maternal substance use are also reported.

Conclusions

While human neuroimaging research converges in showing that maternal substance use is associated with differential reactivity to infant affective cues, further multi-level/multi-modal, longitudinal, and dimensional research is critically needed to advance this area of investigation.

Seven computations of the social brain

The social environment presents the human brain with the most complex information processing demands. The computations that the brain must perform occur in parallel, combine social and nonsocial cues, produce verbal and nonverbal signals and involve multiple cognitive systems, including memory, attention, emotion and learning. This occurs dynamically and at timescales ranging from milliseconds to years. Here, we propose that during social interactions, seven core operations interact to underwrite coherent social functioning; these operations accumulate evidence efficiently-from multiple modalities-when inferring what to do next. We deconstruct the social brain and outline the key components entailed for successful human-social interaction. These include (i) social perception; (ii) social inferences, such as mentalizing; (iii) social learning; (iv) social signaling through verbal and nonverbal cues; (v) social drives (e.g. how to increase one's status); (vi) determining the social identity of agents, including oneself and (vii) minimizing uncertainty within the current social context by integrating sensory signals and inferences. We argue that while it is important to examine these distinct aspects of social inference, to understand the true nature of the human social brain, we must also explain how the brain integrates information from the social world.

Determinants of changes in women's and men's eating behavior across the transition to parenthood: a focus group study

Background

During the pregnancy and postpartum period, both women and men experience physiological and psychological changes, which may negatively impact their eating behavior. A clear understanding of determinants of changes in eating behavior during this period is needed to facilitate the development of targeted family-based interventions countering unfavorable dietary changes during this critical life period.

Methods

Thirteen focus group discussions targeting determinants of changes in eating behavior during pregnancy and postpartum were conducted, involving a total of 74 expecting and first-time parents. A semi-structured question guide was used to facilitate the discussions. An inductive thematic approach was used to derive main and sub-categories of determinants from the data. The Determinants of Nutrition and Eating (DONE)-framework was employed to systematically organize and label the categories and determinants.

Results

Two frameworks were developed; one for the pregnancy and one for the postpartum period, comprising determinants of changes in eating behavior in both women and men. Three main levels of determinants were identified: (1) the individual level, including psychological (e.g., ‘health consciousness’), situational (e.g., ‘effort and convenience’) and biological (e.g., ‘discomfort’); (2) the interpersonal level (e.g., ‘social influence’) and (3) the environmental level, including micro- and meso/macro (e.g., ‘home/environment food availability’). Determinants acting as barriers (e.g., ‘time constraints’) or facilitators (e.g., ‘being a role model’) were identified. Many determinants were mentioned during both (e.g., ‘food knowledge’) or just one investigated period (e.g., ‘physiological changes’ during pregnancy, ‘influence of the baby’ postpartum). Finally, some were described by both parents (e.g., ‘self-regulation’), whereas others were mentioned by women (e.g., ‘(perceived) food safety’) or men (e.g., ‘other priorities’) only.

Conclusion

The developed frameworks set the foundation for the development of future family-based interventions and may be used already by healthcare providers to provide dietary guidance and support for women and men transitioning into parenthood. A focus on the interplay of individual factors at the biological and psychological level together with situational difficulties during pregnancy is recommended. Postpartum, focus should go to support first-time parents to obtain balance of both maintaining one’s own health and taking care of the baby, on improving self-regulation skills, and on coping with related situational constraints.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01137-4.

Not all "caregivers" are created equal: Liking, caring and facial expression responses to the baby schema as a function of parenthood and testosterone

The baby schema elicits care from potential caregivers. However, much of the research on the baby schema is based on self-report only. To address this issue, we explored the effects of baby schema and child age on facial expressions (EMG) and eye-blink startle, in addition to self-reported liking and caring for 43 men and 48 women (39 parents). Further, basal testosterone was assessed. All groups responded with liking and caring to high baby schema, but only women also responded with more positive facial expressions. Caring and smiling towards infants compared to first graders depended on parenthood and testosterone levels. Basal testosterone levels were negatively associated with overall responsiveness to children in women and fathers, but positively in non-fathers. Whereas the baby schema overall lead to positive affect and caring, the scope of these responses and the processes underlying them depended on gender, parenthood and hormonal status.

A systematic review of human paternal oxytocin: Insights into the methodology and what we know so far

With the consolidation of fathers' engagement in caregiving, understanding the neuroendocrine and hormonal mechanisms underlying fatherhood becomes a relevant topic. Oxytocin (OT) has been linked with maternal bonding and caregiving, but less is known about the role of OT in human fatherhood and paternal caregiving. A systematic review of methods and findings of previous OT research in human fathers was carried. The literature search on PubMed and Scopus yielded 133 records. Twenty-four studies were included and analyzed. Significant variability emerged in OT methodology, including laboratory tasks, assessment methods, and outcome measures. Fathers' OT levels appear to increase after childbirth. OT was significantly correlated with less hostility and with the quality of paternal physical stimulation in play interactions, but not with paternal sensitivity. Fathers' and children's OT levels were significantly correlated in a limited subset of studies, intriguingly suggesting that cross-generational OT regulation may occur during the early years of life. This study highlights relevant issues and limitations of peripheral OT assessment in human subjects, especially in fathers. Although the study of paternal neuroendocrinology appears promising, coping with these issues requires dedicated efforts and methodological suggestions are provided to guide future advances in this field.

The Paternal Transition Entails Neuroanatomic Adaptations that are Associated with the Father's Brain Response to his Infant Cues

The transition into fatherhood is a life-changing event that requires substantial psychological adaptations. In families that include a father figure, sensitive paternal behavior has been shown to positively impact the infant’s development. Yet, studies exploring the neuroanatomic adaptations of men in their transition into fatherhood are scarce. The present study used surface-based methods to reanalyze a previously published prospective magnetic resonance imaging dataset comprised of 20 first-time fathers (preconception-to-postpartum) and 17 childless men. We tested if the transition into fatherhood entailed changes in cortical volume, thickness, and area and whether these changes were related to 2 indicators of paternal experience. Specifically, we tested if such changes were associated with (1) the baby’s age and/or (2) the fathers’ brain activity in response to pictures of their babies compared with an unknown baby. Results indicated that first-time fathers exhibited a significant reduction in cortical volume and thickness of the precuneus. Moreover, higher volume reduction and cortical thinning were associated with stronger brain responses to pictures of their own baby in parental brain regions. This is the first study showing preconception-to-postpartum neuroanatomical adaptations in first-time fathers associated with the father’s brain response to cues of his infant.

Temperamental Development among Preterm Born Children. An RCT Follow-Up Study

A randomized controlled trial study recruited 146 preterm born children, either to participate in a modified version of the Mother–Infant Transaction Program (MITP-m) or to receive the usual follow-up services, before and after discharge from a neonatal intensive care unit. This follow-up study investigates whether MITP participation is associated with parental perceptions of child temperament from two to seven years. Children’s temperament was reported by mothers and fathers separately at children’s ages of 2, 3, 5, and 7 years. Parents in the MITP-m group reported lower levels of negative emotionality in their children compared to the control group. In maternal reports, a group effect (F(1, 121) = 9.7, p = 0.002) revealed a stable difference in children’s negative emotionality from two to seven years, while a group-by-time interaction related to an increasing difference was detected in reports from fathers (F(1, 94) = 4.8, p = 0.03). Another group difference appeared in fathers’ reports of children’s soothability (F(1, 100) = 14.2, p < 0.0005). MITP-m fathers seemed to perceive their children as easier to soothe at all ages as no interaction with time appeared. Parental reports on children’s sociality, shyness, and activity did not differ between the groups.

Father-infant interactions and infant regional brain volumes: A cross-sectional MRI study

Fathers play a crucial role in their children’s socio-emotional and cognitive development. A plausible intermediate phenotype underlying this association is father’s impact on infant brain. However, research on the association between paternal caregiving and child brain biology is scarce, particularly during infancy. Thus, we used magnetic resonance imaging (MRI) to investigate the relationship between observed father–infant interactions, specifically paternal sensitivity, and regional brain volumes in a community sample of 3-to-6-month-old infants (N = 28). We controlled for maternal sensitivity and examined the moderating role of infant communication on this relationship. T2-weighted MR images were acquired from infants during natural sleep. Higher levels of paternal sensitivity were associated with smaller cerebellar volumes in infants with high communication levels. In contrast, paternal sensitivity was not associated with subcortical grey matter volumes in the whole sample, and this was similar in infants with both high and low communication levels. This preliminary study provides the first evidence for an association between father-child interactions and variation in infant brain anatomy.

Pathways Relating the Neurobiology of Attachment to Drug Addiction

Substance use disorders constitute a significant public health problem in North America and worldwide. Specifically, substance addictions in women during pregnancy or in the postpartum period have adverse effects not only on the mother, but also on mother-infant attachment and the child's subsequent development. Additionally, there is growing evidence suggesting that parental addiction may be transmitted intergenerationally, where the child of parents with addiction problems is more likely to experience addiction as an adult. The current review takes a developmental perspective and draws from animal and human studies to examine how compromised early experience, including insecure attachment, early abuse/neglect, and unresolved trauma, may influence the development of neurobiological pathways associated with addictions, ultimately increasing one's susceptibility to addictions later in life. We approach this from three different levels: molecular, neuroendocrine and behavioral; and examine the oxytocin affiliation system, dopamine reward system, and glucocorticoid stress response system in this regard. Increased understanding of these underlying mechanisms may help identify key targets for early prevention efforts and inform needed intervention strategies related to both insecure attachment and addiction.