Affiliation buffers stress: cumulative genetic risk in oxytocin-vasopressin genes combines with early caregiving to predict PTSD in war-exposed young children

How shared versus unshared parental contribution to child risk influences guilt responses

The extent to which parents experience guilt related to their child's health may depend on their perceptions of their contribution to these outcomes. The impact of the child's "other" biological parent's (OBP) contribution to child health on guilt responses is understudied. Some models posit a diffusion-of-responsibility process, while others favor a heightened-risk-heightened-guilt model. The present study examines how perceived OBP contribution to child risk affects guilt among a sample of parents with self-reported overweight. Parents who perceived their child's OBP to also have overweight experienced more guilt for passing down genetic and family environment-based obesity risk to their child, which suggests that perceptions of shared risk contribution promote guilt-related outcomes. Additionally, risk information endorsing a gene-environment interaction liability framing was the most responsive to OBP weight status. These results support a heightened-risk-heightened-guilt process. Future work should consider guilt when developing child health interventions to avoid undesirable emotional outcomes among parents.

Continuity of psychopathology v. resilience across the transition to adolescence: role of hair cortisol and sensitive caregiving

BACKGROUND

The transition to adolescence implicates heightened vulnerability alongside increased opportunities for resilience. Contexts of early life stress (ELS) exacerbate risk; still, little research addressed biobehavioral mediators of risk and resilience across the adolescent transition following ELS. Utilizing a unique cohort, we tested biosocial moderators of chronicity in adolescents' internalizing disorders v. resilience.

METHOD

Families exposed to chronic war-related trauma, v. controls, were followed. We utilized data from three time-points framing the adolescent transition: late childhood (N = 177, Mage = 9.3 years ± 1.41), early adolescence (N = 111, Mage = 11 0.66 years ± 1.23), and late adolescence (N = 138, Mage = 15.65 years ± 1.31). In late childhood and late adolescence children's internalizing disorders were diagnosed. At early adolescence maternal and child's hair cortisol concentrations (HCC), maternal sensitivity, and mothers' post-traumatic symptoms evaluated.

RESULTS

War-exposed children exhibited more internalizing disorders of chronic trajectory and mothers were less sensitive and more symptomatic. Three pathways elucidated the continuity of psychopathology: (a) maternal sensitivity moderated the risk of chronic psychopathology, (b) maternal post-traumatic symptoms mediated continuity of risk, (c) trauma exposure moderated the association between child internalizing disorders at late childhood and maternal HCC, which linked with child HCC. Child HCC linked with maternal post-traumatic symptoms, which were associated with child disorders in late adolescence.

CONCLUSION

Results demonstrate the complex interplay of maternal and child's biosocial factors as mediators and moderators of risk chronicity across the adolescent transition following trauma. Findings are first to utilize maternal and child's HCC as biomarkers of chronic stress v. resilience during adolescence, a period of neural reorganization and personal growth that shapes the individual's lifetime adaptation.

The Long-Term Effects of Living in a Shared and Continuous Traumatic Reality: The Case of Israeli Families on the Border With Gaza

This article presents a literature review of the concept of intergenerational transmission of traumatic stress among a specific population of Israeli parents and children living near the Israeli/Gaza border, an area that can essentially be viewed as a laboratory of shared, continuous, and stressful reality resulting from ongoing political violence. The Google Scholar database was used to search only for peer-reviewed articles written in English and published between 2002 and 2020, and the particular focus of the study was Israeli families living in the "Gaza envelope": communities that have been on the receiving end of rockets and mortars from Gaza for the past 20 years. The review was based on 35 articles and sheds light on the existence of studies using a variety of perspectives (e.g., psychological, biopsychosocial, and behavioral). Findings demonstrate the effects of continuous stress situations on the family dynamic, even before birth, among this small population. In addition, they show that to understand the unique process of intergenerational trauma transmission in a shared continuous traumatic reality, it is important to adopt a comprehensive perspective so as to understand the reciprocal, long-lasting, and transgenerational effects of being exposed to traumatic stress. This perspective can be used as a basis for developing family intervention strategies that are appropriate for preventing stress outcomes that derive from living in the context of persistent violence.

Postoperative opioid administration and post-traumatic stress symptoms in preschool children after cardiac surgery

PURPOSE

The purpose of this study was to explore relationships between postoperative opioid administration and posttraumatic stress symptoms (PTSS) in preschool-aged children surviving cardiac surgery.

DESIGN AND METHODS

This was a cross-sectional, descriptive study using survey administration and medical chart review. Primary caregivers of children aged three to six years who underwent cardiac surgery at our institution between 2018 and 2020 were invited to participate. Opioid administration was calculated according to morphine milligram equivalents and indexed to the child's body weight. Caregivers completed the Young Child Posttraumatic Stress Disorder Checklist to explore child PTSS. We used correlational methods to assess the strength and direction of relationships between postoperative opioid administration and child PTSS.

RESULTS

We did not find a statistically significant relationship between total postoperative opioid administration and child PTSS. When analyzing individual opioid agents, morphine did show a significant inverse relationship to YCPC scores (r_s = -.57, p = .017) in children with single ventricle physiology.

CONCLUSIONS

Total postoperative opioid administration was not statistically significantly related to child PTSS in our sample. Differing patterns of association were noted among children with single- versus bi-ventricular physiology. Postoperative morphine administration was favorably associated with PTSS in children with single-ventricle physiology.

PRACTICE IMPLICATIONS

Nurses caring for preschool children who undergo cardiac surgery should anticipate the potential development of PTSS in their patients. Studies using larger sample sizes and longitudinal design are needed to replicate the significant relationship between morphine administration and PTSS in preschoolers with single-ventricle physiology.

Oxytocin: An Old Hormone, A Novel Psychotropic Drug And Possible Use In Treating Psychiatric Disorders

BACKGROUND

Oxytocin is a nonapeptide synthesized in the paraventricular and supraoptic nuclei of the hypothalamus. Historically, this molecule has been involved as a key factor in the formation of infant attachment, maternal behavior and pair bonding and, more generally, in linking social signals with cognition, behaviors and reward. In the last decades, the whole oxytocin system has gained a growing interest as it was proposed to be implicated in etiopathogenesis of several neurodevelopmental and neuropsychiatric disorders.

METHODS

With the main goal of an in-depth understanding of the oxytocin role in the regulation of different functions and complex behaviors as well as its intriguing implications in different neuropsychiatric disorders, we performed a critical review of the current state of art. We carried out this work through PubMed database up to June 2021 with the search terms: 1) "oxytocin and neuropsychiatric disorders"; 2) "oxytocin and neurodevelopmental disorders"; 3) "oxytocin and anorexia"; 4) "oxytocin and eating disorders"; 5) "oxytocin and obsessive-compulsive disorder"; 6) "oxytocin and schizophrenia"; 7) "oxytocin and depression"; 8) "oxytocin and bipolar disorder"; 9) "oxytocin and psychosis"; 10) "oxytocin and anxiety"; 11) "oxytocin and personality disorder"; 12) "oxytocin and PTSD".

RESULTS

Biological, genetic, and epigenetic studies highlighted quality and quantity modifications in the expression of oxytocin peptide or in oxytocin receptor isoforms. These alterations would seem to be correlated with a higher risk of presenting several neuropsychiatric disorders belonging to different psychopathological spectra. Collaterally, the exogenous oxytocin administration has shown to ameliorate many neuropsychiatric clinical conditions.

CONCLUSION

Finally, we briefly analyzed the potential pharmacological use of oxytocin in patient with severe symptomatic SARS-CoV-2 infection due to its anti-inflammatory, anti-oxidative and immunoregulatory properties.

Attachment Style Moderates Polygenic Risk for Incident Posttraumatic Stress in U.S. Military Veterans: A 7-Year, Nationally Representative, Prospective Cohort Study

BACKGROUND

Posttraumatic stress disorder (PTSD) develops consequent to complex gene-by-environment interactions beyond the precipitating trauma. To date, however, no known study has used a prospective design to examine how polygenic risk scores (PRSs) interact with social-environmental factors such as attachment style to predict PTSD development.

METHODS

PRSs were derived from a genome-wide association study of PTSD symptoms (N = 186,689; Million Veteran Program cohort). We evaluated combined effects of PRS and attachment style in predicting incident PTSD in a 7-year, nationally representative cohort of trauma-exposed, European-American U.S. military veterans without PTSD (N = 1083). We also conducted multivariate gene-by-environment interaction and drug repositioning analyses to identify loci that interact with multiple environmental factors and potential pharmacotherapies that may be repurposed for this disorder.

RESULTS

Veterans with higher PTSD PRS were more likely to have an incident-positive screen for PTSD over 7 years. A gene-by-environment interaction was also observed, such that higher PRS only predicted incident PTSD in veterans with an insecure attachment style and not those with a secure attachment style. At an individual locus level, the strongest gene-by-environment interaction was observed for the rs4702 variant of the FURIN gene with cumulative lifetime trauma burden. Drug repositioning revealed that genes implicated in PRS are perturbated by the drug doxylamine.

CONCLUSIONS

Attachment style moderates polygenic risk for the development of PTSD in European-American veterans. These findings may inform PTSD prevention and treatment for veterans with high polygenic risk for PTSD and suggest a potential pharmacotherapeutic target for risk genes moderated by social-environmental factors.

The role of maternal trauma and discipline types in emotional processing among Syrian refugee children

Stressful experiences in armed conflict incur intergenerational effects through parental behaviors with their children. A recent study reported that among Syrian refugee families, mothers' (but not fathers') post-traumatic stress (PTS) impacted children's emotional processing. In this study, we aim to shed further light on this phenomenon by analyzing how the parenting practices in the context of post-traumatic stress confers protection or risk for children's emotional processing. Participants were 6-18-year-old children (n = 212) and their mothers (n = 94), who fled from Syria and were residing in Turkish communities. We used the computer-based emotional processing task including photos of facial movements typically associated with different emotions to measure children's capacity for emotional processing. Mothers reported their PTS and the discipline types they use, as well as the contextual factors related to their refugee background. Linear mixed effect models were constructed first, to find out the discipline types that are most strongly associated with emotional processing of the child, and second, to examine whether these discipline types moderate the effect of maternal PTS on children's emotional processing. Finally, generalized linear models were constructed to examine which contextual factors are associated with the use of these discipline types by mothers. We found that spanking as a discipline type was associated with poorer child emotional processing, whereas withholding of media access was associated with better emotional processing. Younger and less religious mothers were more prone to use spanking. The study underlines the need for parenting programs alongside with efforts to address mental health issues among mothers living under armed conflict.

Roles of Oxytocin in Stress Responses, Allostasis and Resilience

Oxytocin has been revealed to work for anxiety suppression and anti-stress as well as for psychosocial behavior and reproductive functions. Oxytocin neurons are activated by various stressful stimuli. The oxytocin receptor is widely distributed within the brain, and oxytocin that is released or diffused affects behavioral and neuroendocrine stress responses. On the other hand, there has been an increasing number of reports on the role of oxytocin in allostasis and resilience. It has been shown that oxytocin maintains homeostasis, shifts the set point for adaptation to a changing environment (allostasis) and contributes to recovery from the shifted set point by inducing active coping responses to stressful stimuli (resilience). Recent studies have suggested that oxytocin is also involved in stress-related disorders, and it has been shown in clinical trials that oxytocin provides therapeutic benefits for patients diagnosed with stress-related disorders. This review includes the latest information on the role of oxytocin in stress responses and adaptation.

The novel vasopressin receptor (V1aR) antagonist SRX246 reduces anxiety in an experimental model in humans: a randomized proof-of-concept study

RATIONALE

Arginine vasopressin (AVP) is a neuropeptide that modulates both physiological and emotional responses to threat. Until recently, drugs that target vasopressin receptors (V1a) in the human central nervous system were unavailable. The development of a novel V1a receptor antagonist, SRX246, permits the experimental validation of vasopressin's role in the regulation of anxiety and fear in humans.

OBJECTIVES

Here, we examined the effects of SRX246 in a proof-of-concept translational paradigm of fear (phasic response to imminent threat) and anxiety (prolonged response to potential threat).

METHODS

Healthy volunteers received both SRX246 and placebo in a randomized, double-blind, counter-balanced order separated by a 5-7-day wash-out period. Threat consisted of unpleasant electric shocks. The "NPU" threat test probed startle reactivity during predictable threat (i.e., fear-potentiated startle) and unpredictable threat (i.e., anxiety-potentiated startle).

RESULTS

As predicted, SRX246 decreased anxiety-potentiated startle independent of fear-potentiated startle.

CONCLUSIONS

As anxiety-potentiated startle is elevated in anxiety and trauma-associated disorders and decreased by traditional anxiolytics such as SSRIs and benzodiazepines, the V1a receptor is a promising novel treatment target.

Genetic differential susceptibility to the parent-child relationship quality and the life span development of compassion

The development of compassion for others might be influenced by the social experiences made during childhood and has a genetic component. No research has yet investigated whether the parent-child relationship quality interacts with genetic variation in the oxytocin and dopamine systems in predicting compassion over the life span. In the prospective Young Finns Study (N = 2099, 43.9% men), we examined the interaction between mother-reported emotional warmth and intolerance toward their child assessed in 1980 (age of participants, 3-18 years) and two established genetic risk scores for oxytocin levels and dopamine signaling activity. Dispositional compassion for others was measured with the Temperament and Character Inventory 1997, 2001, and 2012 (age of participants, 20-50 years). We found a gene-environment interaction (p = .031) that remained marginally significant after adjustment for multiple testing. In line with the differential susceptibility hypothesis, only participants who carry alleles associated with low dopamine signaling activity had higher levels of compassion when growing up with emotionally warm parents, whereas they had lower levels of compassion when their parents were emotionally cold. Children's genetic variability in the dopamine system might result in plasticity to early environmental influences that have a long-lasting effect on the development of compassion. However, our findings need replication.

Is PTSD-Phenotype Associated with HPA-Axis Sensitivity? Feedback Inhibition and Other Modulating Factors of Glucocorticoid Signaling Dynamics

Previously, we found that basal corticosterone pulsatility significantly impacts the vulnerability for developing post-traumatic stress disorder (PTSD). Rats that exhibited PTSD-phenotype were characterized by blunted basal corticosterone pulsatility amplitude and a blunted corticosterone response to a stressor. This study sought to identify the mechanisms underlining both the loss of pulsatility and differences in downstream responses. Serial blood samples were collected manually via jugular vein cannula at 10-min intervals to evaluate suppression of corticosterone following methylprednisolone administration. The rats were exposed to predator scent stress (PSS) after 24 h, and behavioral responses were assessed 7 days post-exposure for retrospective classification into behavioral response groups. Brains were harvested for measurements of the glucocorticoid receptor, mineralocorticoid receptor, FK506-binding protein-51 and arginine vasopressin in specific brain regions to assess changes in hypothalamus–pituitary–adrenal axis (HPA) regulating factors. Methylprednisolone produced greater suppression of corticosterone in the PTSD-phenotype group. During the suppression, the PTSD-phenotype rats showed a significantly more pronounced pulsatile activity. In addition, the PTSD-phenotype group showed distinct changes in the ventral and dorsal CA1, dentate gyrus as well as in the paraventricular nucleus and supra-optic nucleus. These results demonstrate a pre-trauma vulnerability state that is characterized by an over-reactivity of the HPA and changes in its regulating factors.

Chronic early trauma impairs emotion recognition and executive functions in youth; specifying biobehavioral precursors of risk and resilience

Exposure to chronic early trauma carries lasting effects on children's well-being and adaptation. Guided by models on resilience, we assessed the interplay of biological, emotional, cognitive, and relational factors in shaping two regulatory outcomes in trauma-exposed youth: emotion recognition (ER) and executive functions (EF). A unique war-exposed cohort was followed from early childhood to early adolescence. At preadolescence (11-13 years), ER and EF were assessed and respiratory sinus arrhythmia (RSA), biomarker of parasympathetic regulation, was quantified. Mother-child dyadic reciprocity, child's avoidance symptoms, and cortisol (CT) were measured in early childhood. Trauma-exposed youth displayed impaired ER and EF abilities. Conditional process analysis described two differential indirect paths leading from early trauma to regulatory outcomes. ER was mediated by avoidance symptoms in early childhood and modulated by cortisol, such that this path was evident only for preadolescents with high, but not low, CT. In comparison, EF was mediated by the degree of dyadic reciprocity experienced in early childhood and modulated by RSA, observed only among youth with lower RSA. Findings pinpoint trauma-related disruptions to key regulatory support systems in preadolescence as mediated by early-childhood relational, clinical, and physiological factors and highlight the need to specify biobehavioral precursors of resilience toward targeted early interventions.

Limbic Neuropeptidergic Modulators of Emotion and Their Therapeutic Potential for Anxiety and Post-Traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is characterized by hypervigilance, increased reactivity to unpredictable versus predictable threat signals, deficits in fear extinction, and an inability to discriminate between threat and safety. First-line pharmacotherapies for psychiatric disorders have limited therapeutic efficacy in PTSD. However, recent studies have advanced our understanding of the roles of several limbic neuropeptides in the regulation of defensive behaviors and in the neural processes that are disrupted in PTSD. For example, preclinical studies have shown that blockers of tachykinin pathways, such as the Tac2 pathway, attenuate fear memory consolidation in mice and thus might have unique potential as early post-trauma interventions to prevent PTSD development. Targeting this pathway might also be beneficial in regulating other symptoms of PTSD, including trauma-induced aggressive behavior. In addition, preclinical and clinical studies have shown the important role of angiotensin receptors in fear extinction and the promise of using angiotensin II receptor blockade to reduce PTSD symptom severity. Additional preclinical studies have demonstrated that the oxytocin receptors foster accurate fear discrimination by facilitating fear responses to predictable versus unpredictable threats. Complementary human imaging studies demonstrate unique neural targets of intranasal oxytocin and compare its efficacy with well-established anxiolytic treatments. Finally, promising data from human subjects have demonstrated that a selective vasopressin 1A receptor antagonist reduces anxiety induced by unpredictable threats. This review highlights these novel promising targets for the treatment of unique core elements of PTSD pathophysiology.

Social Behavior as a Transdiagnostic Marker of Resilience

The recent shift from psychopathology to resilience and from diagnosis to functioning requires the construction of transdiagnostic markers of adaptation. This review describes a model of resilience that is based on the neurobiology of affiliation and the initial condition of mammals that mature in the context of the mother's body and social behavior. The model proposes three tenets of resilience-plasticity, sociality, and meaning-and argues that coordinated social behavior stands at the core sustaining resilience. Two lines in the maturation of coordinated social behavior are charted, across animal evolution and throughout human development, culminating in the mature human reciprocity of empathy, mutuality, and perspective-taking. Cumulative evidence across ages and clinical conditions and based on our behavioral coding system demonstrates that social reciprocity, defined by plasticity at the individual, dyadic, and group levels, denotes resilience, whereas the two poles of disengagement/avoidance and intrusion/rigidity characterize specific psychopathologies, each with a distinct behavioral signature. Attention to developmentally sensitive markers and to the dimension of meaning in human sociality may open new, behavior-based pathways to resilience.

Alterations in fear extinction neural circuitry and fear-related behavior linked to trauma exposure in children

Exposure to childhood trauma is extremely common (>60 %) and is a leading risk factor for fear-based disorders, including anxiety and posttraumatic stress disorder. These disorders are characterized by deficits in fear extinction and dysfunction in underlying neural circuitry. Given the strong and pervasive link between childhood trauma and the development of psychopathology, fear extinction may be a key mechanism. The present study tests the impact of childhood trauma exposure on fear extinction and underlying neural circuitry. Children (N = 44, 45 % trauma-exposed; 6-11 yrs) completed a novel two-day virtual reality fear extinction experiment. On day one, participants underwent fear conditioning and extinction. Twenty-four hours later, participants completed a test of extinction recall during fMRI. Conditioned fear was measured throughout the experiment using skin conductance and fear-related behavior, and activation in fear-related brain regions was estimated during recall. There were no group differences in conditioned fear during fear conditioning or extinction learning. During extinction recall, however, trauma-exposed children kept more distance from both the previously extinguished and the safety cue, suggesting poor differentiation between threat and safety cues. Trauma-exposed youth also failed to approach the previously extinguished cue over the course of extinction recall. The effects on fear-related behavior during extinction recall were accompanied by higher activation to the previously extinguished cue in fear-relevant brain regions, including the dorsal anterior cingulate cortex and anterior insula, in trauma-exposed relative to control children. Alterations in fear-related brain regions and fear-related behavior may be a core mechanism through which childhood trauma confers heightened vulnerability to psychopathology.

What is resilience: an affiliative neuroscience approach

Resilience - a key topic in clinical science and practice - still lacks a clear conceptualization that integrates its evolutionary and human-specific features, refrains from exclusive focus on fear physiology, incorporates a developmental approach, and, most importantly, is not based on the negation (i.e., absence of symptoms following trauma). Building on the initial condition of mammals, whose brain matures in the context of the mother's body and caregiving behavior, we argue that systems and processes that participate in tuning the brain to the social ecology and adapting to its hardships mark the construct of resilience. These include the oxytocin system, the affiliative brain, and biobehavioral synchrony, all characterized by great flexibility across phylogenesis and ontogenesis. Three core features of resilience are outlined: plasticity, sociality and meaning. Mechanisms of sociality by which coordinated action supports diversity, endurance and adaptation are described across animal evolution. Humans' biobehavioral synchrony matures from maternal attuned behavior in the postpartum to adult-adult relationships of empathy, perspective-taking and intimacy, and extends from the mother-child relationship to other affiliative bonds throughout life, charting a fundamental trajectory in the development of resilience. Findings from three high-risk cohorts, each tapping a distinct disruption to maternal-infant bonding (prematurity, maternal depression, and early life stress/trauma), and followed from birth to adolescence/young adulthood, demonstrate how components of the neurobiology of affiliation confer resilience and uniquely shape the social brain.

Cumulative Risk on Oxytocin-Pathway Genes Impairs Default Mode Network Connectivity in Trauma-Exposed Youth

Background: Although the default mode network (DMN) is a core network essential for brain functioning, little is known about its developmental trajectory, particularly on factors associated with its coherence into a functional network. In light of adult studies indicating DMN's susceptibility to stress-related conditions, we examined links between variability on oxytocin-pathway genes and DMN connectivity in youth exposed to chronic war-related trauma Methods: Following a cohort of war-exposed children from early childhood, we imaged the brains of 74 preadolescents (age 11-13 years; 39 war-exposed) during rest using magnetoencephalography (MEG). A cumulative risk index on oxytocin-pathway genes was constructed by combining single nucleotide polymorphisms on five genes previously linked with social deficits and psychopathology; OXTR rs1042778, OXTR rs2254298, OXTRrs53576, CD38 rs3796863, and AVPR1A RS3. Avoidant response to trauma reminders in early childhood and anxiety disorders in late childhood were assessed as predictors of disruptions to DMN theta connectivity. Results: Higher vulnerability on oxytocin-pathway genes predicted greater disruptions to DMN theta connectivity. Avoidant symptoms in early childhood and generalized anxiety disorder in later childhood were related to impaired DMN connectivity. In combination, stress exposure, oxytocin-pathway genes, and stress-related symptoms explained 24.6% of the variance in DMN connectivity, highlighting the significant effect of stress on the maturing brain. Conclusions: Findings are the first to link the oxytocin system and maturation of the DMN, a core system sustaining autobiographical memories, alteration of intrinsic and extrinsic attention, mentalization, and sense of self. Results suggest that oxytocin may buffer the effects of chronic early stress on the DMN, particularly theta rhythms that typify the developing brain.

The role of oxytocinergic genes in the intergenerational transmission of parent-child relationship qualities

Parenting qualities are known to transmit across generations, but less is known about genetic processes that may modify how strongly parenting quality carries across generations. We examined in prospective data whether oxytocinergic genes of offspring moderate the intergenerational transmission of warm and accepting parent-child relationship qualities. The sample comprised 1167 Finnish parents (G2, 62% female) and their mothers (G1). At the study baseline, G1 mothers (Mage = 38) reported parent-child relationship qualities towards G2 children (age range 3-18). After 28-34 years, G2 offspring reported parent-child relationship qualities towards their own children using the same questionnaire. A cumulative genetic score was computed for G2 by summing up previously identified four alleles associated with non-optimal parenting or social impairments across OXTR (rs1042778, rs2254298, rs53576) and CD38 (rs3796863) genes. Results indicated no interaction effects of G2 cumulative genetic score on the transmission of parent-child relationship qualities. Among single polymorphisms in OXTR, the interaction effects of rs53576 and rs1042778 were found. G1 maternal emotional warmth was associated with higher G2 emotional warmth among G2 participants with the OXTR rs53576 AA/AG genotype, but not among those with the GG genotype. G1 maternal acceptance was associated with higher G2 acceptance among those G2 participants with the OXTR rs1042778 GG/GT genotype, but not among those with the TT genotype. Oxytocinergic genes may influence sensitivity to quality of parent-child relationship, although this needs replication in future studies.

Maternal major depression and synchrony of facial affect during mother-child interactions

Maternal history of Major Depressive Disorder (MDD) dramatically increases children's risk for developing depression, highlighting the critical need for further research on the specific processes involved in the intergenerational transmission of depression. Although previous research suggests that maternal depression may adversely affect the quality of mother-child interactions, less is known about the role of maternal MDD in the moment-to-moment changes in affect that occur during these interactions. The goal of this project, therefore, was to examine synchrony of facial displays of affect during a positive (Vacation Planning) and a negative (Issues Discussion) mother-child interaction, and how this synchrony may be impacted by maternal history of MDD. In doing so, we examined both concurrent and lagged synchrony of facial affect. We recruited 341 mother-child dyads (child average age = 9.30 years; 50.1% girls; 71.6% Caucasian) with and without a maternal history of MDD. Facial electromyography (EMG), continuously recorded during those tasks, was used to index mother and child facial affect. We found that a maternal history of MDD was associated with reduced concurrent synchrony and lagged synchrony (mother facial affect predicting changes in child facial affect) of positive affect during Vacation Planning. Reduced concurrent mother-child synchrony of positive affect during the discussion was also associated with an increase in child self-reported sad affect from before to after the discussion. These findings provide promising initial evidence for how the dynamic exchange of positive affect during mother-child interactions may be disrupted in families with maternal MDD history. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Stress and immune biomarkers interact with parenting behavior to shape anxiety symptoms in trauma-exposed youth

The relations between stress, HPA-axis, and the immune system have been extensively studied; however, no study to date addressed the joint contribution of immune and HPA biomarkers to the development of anxiety in youth exposed to chronic trauma as mediated by mother-child interaction patterns. A unique cohort of war-exposed children and their mothers, compared to matched controls, were followed from infancy and the current study reports findings from early adolescence (mean age = 11.66, SD = 1.23; N = 111; exposed = 58 control = 53). Youth and mothers' salivary cortisol (CT) and secretory immunoglobulin (s-IgA) levels were measured three times during a 4-hour lab visit, mother-child interaction patterns were quantified from a joint task, and children's anxiety symptoms diagnosed. Trauma-exposed children had higher levels of CT and s-IgA, exhibited more anxiety symptoms, and showed lower social collaboration with mother during the joint task. Trauma-exposed mothers had higher CT and s-IgA levels and showed less supportive parenting during mother-child interaction. Structural equation modeling defined three bio-behavioral paths by which trauma increases anxiety in youth. While the first path charted a behavioral link from exposure to child anxiety via diminished maternal support, the other two paths described mediated biological paths, one through HPA-axis functioning, the other via the immune system. Paths via the child's HPA and immune system were mediated by the parallel maternal variable. Findings are the first to describe the complex bio-behavioral interplay of stress and immune biomarkers and parenting behavior in shaping to the development of risk and resilience trajectories in youth growing up amidst chronic trauma.

A Longitudinal Multilevel Study of the "Social" Genotype and Diversity of the Phenotype

Sociability and social domain-related behaviors have been associated with better well-being and endogenous oxytocin levels. Inspection of the literature, however, reveals that the effects between sociability and health outcomes, or between sociability and genotype, are often weak or inconsistent. In the field of personality psychology, the social phenotype is often measured by error-prone assessments based on different theoretical frameworks, which can partly explain the inconsistency of the previous findings. In this study, we evaluated the generalizability of “sociability” measures by partitioning the population variance in adulthood sociability using five indicators from three personality inventories and assessed in two to four follow-ups over a 15-year period (n = 1,573 participants, 28,323 person-observations; age range 20–50 years). Furthermore, we tested whether this variance partition would shed more light to the inconsistencies surrounding the “social” genotype, by using four genetic variants (rs1042778, rs2254298, rs53576, rs3796863) previously associated with a wide range of human social functions. Based on our results, trait (between-individual) variance explained 23% of the variance in overall sociability, differences between sociability indicators explained 41%, state (within-individual) variance explained 5% and measurement errors explained 32%. The genotype was associated only with the sociability indicator variance, suggesting it has specific effects on sentimentality and emotional sharing instead of reflecting general sociability.

Oxytocin receptor gene variants are associated with emotion recognition and resilience, but not with false-belief reasoning performance in healthy young Korean volunteers

AIMS

A growing body of literature has indicated that oxytocin is associated with several domains of social cognition and behavior. Nevertheless, the effects of oxytocin receptor gene (OXTR) polymorphisms on social phenotypes remain unclear. Therefore, we aimed to explore the genetic influence of OXTR variants on social cognition (social perception and theory of mind) and resilience in healthy individuals.

METHODS

We examined the influence of 10 common OXTR variants on social cognitive abilities, including facial emotion recognition and theory of mind, and trait resilience in 264 unrelated, healthy participants.

RESULTS

We found a significant association between the A-C haplotype at rs237887-rs2268490 and facial affect recognition. In addition, the single marker rs2254298 was significantly associated with participants' scores on the Connor-Davidson Resilience Scale. In contrast, variations in OXTR did not affect participants' performance on the false-belief reasoning task.

CONCLUSIONS

Single makers or haplotypes at OXTR may contribute to individual differences in facial emotion recognition and psychological resilience.

Maternal immune and affiliative biomarkers and sensitive parenting mediate the effects of chronic early trauma on child anxiety

BACKGROUND

Chronic early trauma alters children's stress reactivity and increases the prevalence of anxiety disorders; yet the neuroendocrine and immune mechanisms underpinning this effect are not fully clear. Animal studies indicate that the mother's physiology and behavior mediate offspring stress in a system-specific manner, but few studies tested this external-regulatory maternal role in human children exposed to chronic stress.

METHODS

We followed a unique cohort of children exposed to continuous wartime trauma (N = 177; exposed; N = 101, controls; N = 76). At 10 years, maternal and child's salivary immunoglobulin A (s-IgA) and oxytocin (OT), biomarkers of the immune and affiliation systems, were assayed, maternal and child relational behaviors observed, mother and child underwent psychiatric diagnosis, and child anxiety symptoms assessed.

RESULTS

War-exposed mothers had higher s-IgA, lower OT, more anxiety symptoms, and their parenting was characterized by reduced sensitivity. Exposed children showed higher s-IgA, more anxiety disorders and post traumatic stress disorder, and more anxiety symptoms. Path analysis model defined three pathways by which maternal physiology and behavior impacted child anxiety; (a) increasing maternal s-IgA, which led to increased child s-IgA, augmenting child anxiety; (b) reducing maternal OT, which linked with diminished child OT and social repertoire; and (c) increasing maternal anxiety, which directly impacted child anxiety.

CONCLUSIONS

Our findings, the first to measure immune and affiliation biomarkers in mothers and children, detail their unique and joint effects on children's anxiety in response to stress; highlight the relations between chronic stress, immune activation, and anxiety in children; and describe how processes of biobehavioral synchrony shape children's long-term adaptation.

Associations Between Nurse-Guided Variables and Plasma Oxytocin Trajectories in Premature Infants During Initial Hospitalization

BACKGROUND

Oxytocin (OT) is a social hormone that may help researchers understand how nurse-guided interventions during initial infant hospitalization, such as supporting human milk expression, promoting comforting touch, and reducing exposure to stressors, affect preterm brain development.

PURPOSE

To determine whether factors related to human milk, touch, or stressor exposure are related to plasma OT trajectories in premature infants.

METHODS

Plasma from 33 premature infants, born gestational ages 25 to (Equation is included in full-text article.)weeks, was collected at 14 days of life and then weekly until 34 weeks' corrected gestational age (CGA). Variables related to feeding volumes of human milk and formula; touch, as indexed by skin-to-skin contact (SSC) and swaddled holding; and clinical stressors were extracted from the electronic medical record. Linear mixed-models tested associations between nurse-guided variables and plasma OT trajectories.

RESULTS

In the final model, same-day SSC was positively related not only to plasma OT levels at 27 weeks' CGA (β= .938, P = .002) but also to a decline in plasma OT levels over time (β=-.177, P = .001). Volume of enteral feeds (mL/kg/d), its interaction with CGA, and number of stressful procedures were not statistically significant (β= .011, P = .077; β=-.002, P = .066; and β= .007, P = .062, respectively).

IMPLICATIONS FOR PRACTICE

Nurse-guided interventions are associated with infant plasma OT levels, suggesting nurses may impact the neurobiology of the developing premature infant.

IMPLICATIONS FOR RESEARCH

Replication with larger sample sizes and randomized controlled trial designs is needed to test effects of specific nursing interventions on infant OT.

Single-Prolonged Stress: A Review of Two Decades of Progress in a Rodent Model of Post-traumatic Stress Disorder

Post-traumatic stress disorder (PTSD) is a common, costly, and often debilitating psychiatric condition. However, the biological mechanisms underlying this disease are still largely unknown or poorly understood. Considerable evidence indicates that PTSD results from dysfunction in highly-conserved brain systems involved in stress, anxiety, fear, and reward. Pre-clinical models of traumatic stress exposure are critical in defining the neurobiological mechanisms of PTSD, which will ultimately aid in the development of new treatments for PTSD. Single prolonged stress (SPS) is a pre-clinical model that displays behavioral, molecular, and physiological alterations that recapitulate many of the same alterations observed in PTSD, illustrating its validity and giving it utility as a model for investigating post-traumatic adaptations and pre-trauma risk and protective factors. In this manuscript, we review the present state of research using the SPS model, with the goals of (1) describing the utility of the SPS model as a tool for investigating post-trauma adaptations, (2) relating findings using the SPS model to findings in patients with PTSD, and (3) indicating research gaps and strategies to address them in order to improve our understanding of the pathophysiology of PTSD.

Oxytocin and vasopressin neural networks: Implications for social behavioral diversity and translational neuroscience

Oxytocin- and vasopressin-related systems are present in invertebrate and vertebrate bilaterian animals, including humans, and exhibit conserved neuroanatomical and functional properties. In vertebrates, these systems innervate conserved neural networks that regulate social learning and behavior, including conspecific recognition, social attachment, and parental behavior. Individual and species-level variation in central organization of oxytocin and vasopressin systems has been linked to individual and species variation in social learning and behavior. In humans, genetic polymorphisms in the genes encoding oxytocin and vasopressin peptides and/or their respective target receptors have been associated with individual variation in social recognition, social attachment phenotypes, parental behavior, and psychiatric phenotypes such as autism. Here we describe both conserved and variable features of central oxytocin and vasopressin systems in the context of social behavioral diversity, with a particular focus on neural networks that modulate social learning, behavior, and salience of sociosensory stimuli during species-typical social contexts.

Addressing the Needs of Preschool Children in the Context of Disasters and Terrorism: Clinical Pictures and Moderating Factors

PURPOSE OF REVIEW

This paper surveys the existent theoretical and research literature regarding the needs of preschool children in the context of disasters and terrorism with the aim of understanding (a) the consequences of such events for young children and (b) the main moderating variables influencing the event-consequence association to learn how to enhance their resilience.

RECENT FINDINGS

Consequences include a variety of emotional, behavioral, and biological outcomes. Implications for refugee children are discussed. Main moderating variables were mother's sensitivity and mother's PTSD symptoms. Exposure to disasters and terrorism may have severe effects on the mental health and development among preschool children. Future research should explore the implications of different levels of exposure and the effects of moderating psychosocial and biological variables, including the parent-child triad, on the event-consequence relationship.

Effects of War, Terrorism and Armed Conflict on Young Children: A Systematic Review

Millions of children have been maimed, displaced, orphaned and killed in modern warfare that targets civilian populations. Several reviews have documented the impact of political trauma on children's mental health but none has focused specifically on young children (ages 0-6). Since developmental factors influence the young child's perception and experience of traumatic events, this developmental period is characterized by a unique spectrum of responses to political trauma. This systematic review, comprising 35 studies that included a total of 4365 young children, examined the effects of exposure to war, conflict and terrorism on young children and the influence of parental factors on these effects. Results showed that effects include PTSD and post-traumatic stress symptoms, behavioral and emotional symptoms, sleep problems, disturbed play, and psychosomatic symptoms. Correlations emerged between parental and children's psychopathology and, additionally, family environment and parental functioning emerged as moderators of the exposure-outcome association for children.

PTSD: from neurobiology to pharmacological treatments

Posttraumatic stress disorder (PTSD) is a chronic debilitating psychiatric disorder characterized by symptoms of re-experience, avoidance, and hyperarousal that can arise immediately or many years after exposure to a traumatic event and injury. Although extensive research has been done over the past 30 years, the etiology of PTSD remains largely unknown. Several neurobiological systems have been implicated in the pathophysiology and vulnerability for developing PTSD; however, first-line pharmacotherapies are limited. Less than 30% achieve full remission, and even then, approved pharmacological treatments often take weeks for therapeutic effect. This article aims to review the pathophysiology of PTSD within multiple neurobiological systems and how these mechanisms are used as pharmacologic targets of treatment, as well as their potential for future targets of intervention.

Genetic Regulation of Maternal Oxytocin Response and Its Influences on Maternal Behavior

We interrogated the genetic modulation of maternal oxytocin response and its association with maternal behavior using genetic risk scores within the oxytocin receptor (OXTR) gene. We identified a novel SNP, rs968389, to be significantly associated with maternal oxytocin response after a challenging mother-infant interaction task (Still Face Paradigm) and maternal separation anxiety from the infant. Performing a multiallelic analysis across OXTR by calculating a cumulative genetic risk score revealed a significant gene-by-environment (G × E) interaction, with OXTR genetic risk score interacting with adult separation anxiety to modulate levels of maternal sensitivity. Mothers with higher OXTR genetic risk score and adult separation anxiety showed significantly reduced levels of maternal sensitivity during free play with the infant. The same G × E interaction was also observed for the extended OXTR cumulative genetic risk score that included rs968389. Moreover, the extended cumulative OXTR genetic risk score itself was found to be significantly associated with maternal separation anxiety as it specifically relates to the infant. Our results suggest a complex montage of individual and synergistic genetic mediators of maternal behavior. These findings add to specific knowledge about genetic regulation of maternal oxytocin response in relation to maternal adjustment and infant bonding through the first few months of life.

Risk and resilience trajectories in war-exposed children across the first decade of life

BACKGROUND

Although the effects of early-onset trauma on susceptibility to psychopathology are well-acknowledged, no study to date has followed risk and resilience trajectories in war-exposed young children over lengthy periods and charted predictors of individual pathways.

METHOD

In this prospective longitudinal study, we followed 232 children, including 148 exposed to repeated wartime trauma and 84 controls, at three time points: early childhood (1.5-5 years), middle childhood (5-8 years), and late childhood (9-11 years). Children were diagnosed at each time point and four trajectories defined: children exhibiting no pathology at any time point, those displaying early pathology that later remitted, those showing initial resilience followed by late pathology, and children presenting chronic pathology across the entire first decade. Maternal behavioral containment during trauma evocation and child social engagement during free play were observed in early childhood and maternal emotional distress self-reported across time.

RESULTS

War-exposed children showed significantly higher rates of psychopathology, with 81% exhibiting pathology at some point during childhood. In middle childhood, exposed children displayed more posttraumatic stress disorders (PTSD), anxiety disorders, and attention-deficit/hyperactivity disorders (ADHD), and in late childhood more PTSD, conduct/oppositional defiant disorders, and ADHD. War-exposed children had more comorbid psychopathologies and number of comorbidities increased with age. Notably, war-exposure increased prevalence of chronic pathology by 24-fold. Maternal factors, including mother's uncontained style and emotional distress, increased risk for early and chronic psychopathology, whereas reduced child social engagement augmented risk for late pathology.

CONCLUSIONS

Early-onset chronic stress does not heal naturally, and its effects appear to exacerbate over time, with trauma-exposed children presenting a more comorbid, chronic, and externalizing profile as they grow older. Our findings demonstrate that responses to trauma are dynamic and variable and pinpoint age-specific effects of maternal and child factors on risk and resilience trajectories. Results highlight the importance of conducting long-term follow-up studies and constructing individually tailored early interventions following trauma exposure.

Cross-generational influences on childhood anxiety disorders: pathways and mechanisms

Anxiety disorders are common across the lifespan, cause severe distress and impairment, and usually have their onset in childhood. Substantial clinical and epidemiological research has demonstrated the existence of links between anxiety and its disorders in children and parents. Research on the pathways and mechanisms underlying these links has pointed to both behavioral and biological systems. This review synthesizes and summarizes several major aspects of this research. Behavioral systems include vicarious learning, social referencing, and modeling of parental anxiety; overly protective or critical parenting styles; and aspects of parental responses to child anxiety including family accommodation of the child's symptoms. Biological systems include aspects of the prenatal environment affected by maternal anxiety, development and functioning of the oxytocinergic system, and genetic and epigenetic transmission. Implications for the prevention and treatment of child anxiety disorders are discussed, including the potential to enhance child anxiety treatment outcomes through biologically informed parent-based interventions.

Oxytocin Pathway Genes: Evolutionary Ancient System Impacting on Human Affiliation, Sociality, and Psychopathology

Oxytocin (OT), a nonapeptide signaling molecule originating from an ancestral peptide, appears in different variants across all vertebrate and several invertebrate species. Throughout animal evolution, neuropeptidergic signaling has been adapted by organisms for regulating response to rapidly changing environments. The family of OT-like molecules affects both peripheral tissues implicated in reproduction, homeostasis, and energy balance, as well as neuromodulation of social behavior, stress regulation, and associative learning in species ranging from nematodes to humans. After describing the OT-signaling pathway, we review research on the three genes most extensively studied in humans: the OT receptor (OXTR), the structural gene for OT (OXT/neurophysin-I), and CD38. Consistent with the notion that sociality should be studied from the perspective of social life at the species level, we address human social functions in relation to OT-pathway genes, including parenting, empathy, and using social relationships to manage stress. We then describe associations between OT-pathway genes with psychopathologies involving social dysfunctions such as autism, depression, or schizophrenia. Human research particularly underscored the involvement of two OXTR single nucleotide polymorphisms (rs53576, rs2254298) with fewer studies focusing on other OXTR (rs7632287, rs1042778, rs2268494, rs2268490), OXT (rs2740210, rs4813627, rs4813625), and CD38 (rs3796863, rs6449197) single nucleotide polymorphisms. Overall, studies provide evidence for the involvement of OT-pathway genes in human social functions but also suggest that factors such as gender, culture, and early environment often confound attempts to replicate first findings. We conclude by discussing epigenetics, conceptual implications within an evolutionary perspective, and future directions, especially the need to refine phenotypes, carefully characterize early environments, and integrate observations of social behavior across ecological contexts.

The neurobiology of mammalian parenting and the biosocial context of human caregiving

This article is part of a Special Issue "Parental Care". Research on the neurobiology of attachment, pioneered by scholars in the generation that followed the discovery of social bonding, examined the biological basis of mammalian parenting through systematic experiments in animal models and their application to theories on human attachment. This paper argues for the need to construct a theory on the neurobiology of human attachment that integrates findings in animal models with human neuroscience research to formulate concepts based on experimental, not only extrapolative data. Rosenblatt's (2003) three characteristics of mammalian parenting - rapid formation of attachment, behavioral synchrony, and mother-offspring attachment as basis of social organization - are used to guide discussion on mammalian-general versus human-specific attributes of parental care. These highlight specific components of attachment in rodents, primates, and humans that chart the evolution from promiscuous, nest-bound, olfactory-based bonds to exclusive, multi-sensory, and representation-based attachments. Following, three continua are outlined in parental behavior, hormones, and brain, each detailing the evolution from rodents to humans. Parental behavior is defined as a process of trophallaxis - the reciprocal multisensory exchange that supports approach orientation and enables collaboration in social species - and includes human-specific features that enable behavioral synchrony independent of tactile contact. The oxytocin system incorporates conserved and human-specific components and is marked by pulsatile activity and dendritic release that reorganize neural networks on the basis of species-specific attachment experiences. Finally, the subcortical limbic circuit underpinning mammalian mothering extends in humans to include multiple cortical networks implicated in empathy, mentalizing, and emotion regulation that enable flexible, goal-directed caregiving. I conclude by presenting a philosophical continuum from Hobbes to Lorenz, which illustrates how research on the neurobiology of attachment can put in the forefront the social-collaborative elements in human nature and afford a new perspective on the mind-brain polarity.

Inflammatory and Epigenetic Pathways for Perinatal Depression

Depression during the perinatal period is common and can have adverse consequences for women and their children. Yet, the biobehavioral mechanisms underlying perinatal depression are not known. Adverse early life experiences increase the risk for adult depression. One potential mechanism by which this increased risk occurs is epigenetic embedding of inflammatory pathways. The purpose of this article is to propose a conceptual model that explicates the linkage between early life adversity and the risk for maternal depression. The model posits that early life adversity embeds a proinflammatory epigenetic signature (altered DNA methylation) that predisposes vulnerable women to depression during pregnancy and the postpartum period. As proposed, women with a history of early life adversity are more likely to exhibit higher levels of proinflammatory cytokines and lower levels of oxytocin in response to the demands of pregnancy and new motherhood, both of which are associated with the risk for perinatal depression. The model is designed to guide investigations into the biobehavioral basis for perinatal depression, with emphasis upon the impact of early life adversity. Testing this model will provide a better understanding of maternal depressive risk and improve identification of vulnerable women who would benefit from targeted interventions that can reduce the impact of perinatal depression on maternal–infant health.

Effects of intranasal oxytocin on amygdala reactivity to emotional faces in recently trauma-exposed individuals

There is a need for effective, early post-trauma preventive interventions for post-traumatic stress disorder (PTSD). Attenuating amygdala hyperreactivity early post-trauma, a likely PTSD vulnerability factor, may decrease PTSD risk. Since oxytocin modulates amygdala reactivity to emotional stimuli, oxytocin administration early post-trauma may be a promising candidate for PTSD prevention. In a randomized double-blind placebo-controlled fMRI study, we investigated effects of a single intranasal oxytocin administration (40 IU) on amygdala reactivity to happy, neutral and fearful faces in 41 recently trauma-exposed men and women showing moderate to high distress after initial post-trauma screening. We explored treatment interactions with sex. Participants were scanned within 11 days post-trauma. Compared with placebo, oxytocin significantly increased right amygdala reactivity to fearful faces. There was a significant treatment by sex interaction on amygdala reactivity to neutral faces, with women showing increased left amygdala reactivity after oxytocin. These findings indicate that a single oxytocin administration may enhance fearful faces processing in recently trauma-exposed individuals and neutral faces processing in recently trauma-exposed women. These observations may be explained by oxytocin-induced increased salience processing. Clinical implications of these findings for PTSD prevention should be further investigated.

TRIAL REGISTER

Netherlands Trial Registry; Boosting Oxytocin after trauma: Neurobiology and the Development of Stress-related psychopathology (BONDS); NTR3190; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC = 3190.

The oxytocin system promotes resilience to the effects of neonatal isolation on adult social attachment in female prairie voles

Genes and social experiences interact to create variation in social behavior and vulnerability to develop disorders of the social domain. Socially monogamous prairie voles display remarkable diversity in neuropeptide receptor systems and social behavior. Here, we examine the interaction of early-life adversity and brain oxytocin receptor (OTR) density on adult social attachment in female prairie voles. First, pups were isolated for 3 h per day, or unmanipulated, from postnatal day 1-14. Adult subjects were tested on the partner preference (PP) test to assess social attachment and OTR density in the brain was quantified. Neonatal social isolation impaired female PP formation, without affecting OTR density. Accumbal OTR density was, however, positively correlated with the percent of time spent huddling with the partner in neonatally isolated females. Females with high accumbal OTR binding were resilient to neonatal isolation. These results are consistent with the hypothesis that parental nurturing shapes neural systems underlying social relationships by enhancing striatal OTR signaling. Thus, we next determined whether early touch, mimicking parental licking and grooming, stimulates hypothalamic OT neuron activity. Tactile stimulation induced immediate-early gene activity in OT neurons in neonates. Finally, we investigated whether pharmacologically potentiating OT release using a melanocortin 3/4 agonist, melanotan-II (10 mg kg(-1) subcutaneously), would mitigate the social isolation-induced impairments in attachment behavior. Neonatal melanotan-II administration buffered against the effects of early isolation on partner preference formation. Thus, variation in accumbal OTR density and early OT release induced by parental nurturing may moderate susceptibility to early adverse experiences, including neglect.

Sensitive periods in human social development: New insights from research on oxytocin, synchrony, and high-risk parenting

Sensitive periods (SP) in behavioral development appeared in the biological sciences during the first decade of the 20th century, and research in animal models beginning in the 1950s provide terminology and evidence for SP effects. This paper proposes a rigorous program for human SP research and argues that the complexity of the human brain and variability of the human ecology necessitate that SP effects must be studied in humans, employ longitudinal designs starting at birth, test mechanism-based hypotheses based on animal studies that manipulate early environments, and utilize high-risk conditions as “natural experiments.” In light of research on the molecular basis of critical periods and their sequential cascades, it is proposed that the oxytocin (OT) system, an ancient and integrative system that cross-talks with the stress, reward, immune, and brain stem mediated homeostatic systems and supports mammalian sociality, plays a unique role in experience-dependent plasticity that buttresses SP effects due to its (a) dendritic mode of release leading to autoregulated functioning primed by early experience, (b) pulsatile pattern of activity, and (c) special role in neural plasticity at the molecular and network assembly levels. Synchrony, the coordination of biology and behavior during social contact, is suggested as a mechanism by which SP exert their effect on OT functionality, the social brain, and adult sociality. Findings from four high-risk birth cohorts, each followed repeatedly from birth to 10 years, provide unique “natural experiments” for human SP research based on specific programs in animal models. These include prematurity (maternal proximity), multiple birth (peer rearing), postpartum depression (low licking and grooming), and chronic unpredictable trauma (maternal rotation, variable foraging demands). In each cohort, hypotheses are based on the missing environmental component during SP, and findings on social synchrony, OT functionality, stress response, emotion regulation, and mental health accord with the multilevel and dynamic principles of developmental psychopathology. The results on the potential for reparation versus chronicity following early deprivation highlight a flexible conceptualization of resilience based on human SP research. Consideration of SP effects at the molecular, endocrine, brain, and behavioral levels and in relation to the neural plasticity and multifinality of human social functions may assist in fine-tuning early detection and the construction of targeted individualized interventions.

Investigational drugs under development for the treatment of PTSD

INTRODUCTION

Posttraumatic stress disorder (PTSD) is a prevalent, chronic and disabling anxiety disorder that may develop following exposure to a traumatic event. There is currently no effective pharmacotherapy for PTSD and therefore the discovery of novel, evidence-based treatments is particularly important. This review of potential novel treatments could act as a catalyst for further drug investigation.

AREAS COVERED

In this review, the authors discuss the heterogeneity of PTSD and why this provides a challenge for discovering effective treatments for this disorder. By searching for the neurobiological systems that are disrupted in individuals with PTSD and their correlation with different symptoms, the authors propose potential pharmacological treatments that could target these symptoms. They discuss drugs such as nabilone, d-cycloserine, nor-BNI, 7,8-dihydroxyflavone and oxytocin (OT) to target systems such as cannabinoids, glutamate, opioids, brain-derived neurotrophic factor and the OT receptor, respectively. While not conclusive, the authors believe that these brain systems include promising targets for drug discovery. Finally, the authors review animal studies, proof-of-concept studies and case studies that support our proposed treatments.

EXPERT OPINION

A mechanism-based approach utilizing techniques such as in vivo neuroimaging will allow for the determination of treatments. Due to the heterogeneity of the PTSD phenotype, focusing on symptomology rather than a categorical diagnosis will allow for more personalized treatment. Furthermore, there appears to be a promise in drugs as cognitive enhancers, the use of drug cocktails and novel compounds that target specific pathways linked to the etiology of PTSD.

Vasopressin Proves Es-sense-tial: Vasopressin and the Modulation of Sensory Processing in Mammals

As mammals develop, they encounter increasing social complexity in the surrounding world. In order to survive, mammals must show appropriate behaviors toward their mates, offspring, and same-sex conspecifics. Although the behavioral effects of the neuropeptide arginine vasopressin (AVP) have been studied in a variety of social contexts, the effects of this neuropeptide on multimodal sensory processing have received less attention. AVP is widely distributed through sensory regions of the brain and has been demonstrated to modulate olfactory, auditory, gustatory, and visual processing. Here, we review the evidence linking AVP to the processing of social stimuli in sensory regions of the brain and explore how sensory processing can shape behavioral responses to these stimuli. In addition, we address the interplay between hormonal and neural AVP in regulating sensory processing of social cues. Because AVP pathways show plasticity during development, early life experiences may shape life-long processing of sensory information. Furthermore, disorders of social behavior such as autism and schizophrenia that have been linked with AVP also have been linked with dysfunctions in sensory processing. Together, these studies suggest that AVP's diversity of effects on social behavior across a variety of mammalian species may result from the effects of this neuropeptide on sensory processing.

Developing zebrafish models relevant to PTSD and other trauma- and stressor-related disorders

While post-traumatic stress disorder (PTSD) and other trauma- and stress-related disorders (TSRDs) represent a serious societal and public health concern, their pathogenesis is largely unknown. Given the clinical complexity of TSRD development and susceptibility, greater investigation into candidate biomarkers and specific genetic pathways implicated in both risk and resilience to trauma becomes critical. In line with this, numerous animal models have been extensively used to better understand the pathogenic mechanisms of PTSD and related TSRD. Here, we discuss the rapidly increasing potential of zebrafish as models of these disorders, and how their use may aid researchers in uncovering novel treatments and therapies in this field.