What's Love Got to do with it: Role of oxytocin in trauma, attachment and resilience

Beyond Bouncing Back: Exploring Undergraduate Dental Professional Students' Perceptions of Resilience

INTRODUCTION

The first signs of mental health issues in dentistry manifest as early as undergraduate training, thus it is essential to delve into the concept of resilience to equip those studying and working in dentistry with the resources to cultivate a positive mindset.

MATERIALS AND METHODS

A focus group was conducted with a homogenous purposive sample of eight undergraduate dental profession students from all 3 years of study at the University of Portsmouth Dental Academy (UPDA). The six-phase Braun and Clarke's thematic analysis was adopted to interpret patterns in data.

RESULTS

Four themes of: 'definition of resilience'; 'factors enhancing resilience'; 'factors challenging resilience' and 'developing resilience in dentistry'; and 23 subthemes were identified. Students defined resilience as an ability to bounce back from adversity and perceived it as a dynamic and contextual phenomenon that fluctuated due to an interplay of personal, social and environmental factors.

CONCLUSION

The findings of this study showed undergraduate dental profession students' perceptions of resilience, factors influencing it and strategies to develop it. These findings may inform the curriculum of resilience training programmes targeted towards this population.

Reduction of oxytocin plasma levels in borderline personality disorder and normalization induced by psychotherapies

BACKGROUND

Borderline personality disorder (BPD) is a severe mental disorder characterized by emotional dysregulation, impulsive behaviors, and difficulties in interpersonal relationships. Despite the poor understanding of the underlying biological processes, the oxytocin (OXT) system may be involved in and mediate some of BPD's symptomatic and behavioral aspects. To clarify OXT's role in BPD, we assessed its plasma levels and modulations induced by psychotherapies in patients.

METHODS

Fifty BPD patients and 28 healthy controls (HC) participated in the study; patients were randomly assigned to two psychotherapeutic treatments: metacognitive interpersonal therapy and structured clinical management. Clinical and psychometric measures were assessed, and plasma was collected at baseline (T0) and in patients after 6 (T6) and 12 (T12) months of treatment. OXT was quantified by a radioimmunoassay technique.

RESULTS

BPD patients showed lower plasma OXT at T0 than HC (p = 0.002), and a correlation was observed (r = -0.36, p = 0.017) between low OXT concentrations and high Attachment Style Questionnaire - Italian Version-Preoccupation with Relationships subscale scores. OXT changed significantly over time in patients (p = 0.049) with an increase particularly evident from baseline to T6 (p = 0.022), without significant difference between treatment groups. OXT changes (T0 - T12) inversely correlated with symptom improvement as changes in the Zanarini Rating Scale for borderline personality disorder (r = 0.387, p = 0.006) and the Difficulties in Emotion Regulation Scale (r = 0.387, p = 0.005) scores during treatment.

CONCLUSIONS

OXT alteration in BPD patients and the regularizing effect of long-term psychotherapies support an involvement of the OXT system in the disease and in treatment impact. More research is needed to fully understand the underlying causal mechanisms linking OXT with pathogenesis and psychotherapy outcomes.

Veterans' experiences of somatic experiencing and prolonged exposure therapies for post-traumatic stress disorder: A qualitative analysis

PURPOSE

Despite the proliferation of research into evidence based treatment for military PTSD there is little evidence for treatment assignment criterion and military based PTSD still demonstrates low remission rates.

METHOD

Thirty participants in a randomized control trial comparing Prolonged Exposure (PE) and Somatic Experiencing (SE) were interviewed on their experiences in therapy and their responses assessed using a descriptive phenomenological analysis approach to delineate the central tenets of the two therapeutic approaches.

RESULTS

Results indicated that participants from both therapies covered themes of the experience of change, the experience of the therapeutic relationship and the therapeutic process. Within these themes, SE and PE participants reported both similar experiences, such as the predominance of physiological or bodily experiences and also described nuanced differences, specifically pertaining to therapy characteristics. SE participants described the process in terms of learning a language, applicable to alternative scenarios and PE participants described the process in terms of conquering exposures in order to achieve respite from symptoms.

CONCLUSION

The current findings have relevance in terms of presenting the key elements of the distinct trauma therapies and determining treatment appropriateness based on desired outcomes. They highlight the commonalities and differences between the patient experience in PE and SE, specifically the relevance of the bodily response, treatment expertise and therapist characteristics in both treatments. Understanding the unique elements of PE, a gold-standard PTSD treatment and SE, a novel somatic-based psychotherapy, will allow for better treatment preparation for participants and potentially aid treatment assignment.

Endocrine Controls of Skin Aging

Skin is the largest organ of the human body and undergoes both intrinsic (chronological) and extrinsic aging. While intrinsic skin aging is driven by genetic and epigenetic factors, extrinsic aging is mediated by external threats such as UV irradiation or fine particular matters, the sum of which is referred to as exposome. The clinical manifestations and biochemical changes are different between intrinsic and extrinsic skin aging, albeit overlapping features exist, eg, increased generation of reactive oxygen species, extracellular matrix degradation, telomere shortening, increased lipid peroxidation, or DNA damage. As skin is a prominent target for many hormones, the molecular and biochemical processes underlying intrinsic and extrinsic skin aging are under tight control of classical neuroendocrine axes. However, skin is also an endocrine organ itself, including the hair follicle, a fully functional neuroendocrine "miniorgan." Here we review pivotal hormones controlling human skin aging focusing on IGF-1, a key fibroblast-derived orchestrator of skin aging, of GH, estrogens, retinoids, and melatonin. The emerging roles of additional endocrine players, ie, α-melanocyte-stimulating hormone, a central player of the hypothalamic-pituitary-adrenal axis; members of the hypothalamic-pituitary-thyroid axis; oxytocin, endocannabinoids, and peroxisome proliferator-activated receptor modulators, are also reviewed. Until now, only a limited number of these hormones, mainly topical retinoids and estrogens, have found their way into clinical practice as anti-skin aging compounds. Further research into the biological properties of endocrine players or its derivatives may offer the development of novel senotherapeutics for the treatment and prevention of skin aging.

Ginsenoside Rg1 enriches gut microbial indole-3-acetic acid to alleviate depression-like behavior in mice via oxytocin signaling

BACKGROUND AND PURPOSE

Although a large collection of data has shown that ginsenosides, the major active ingredients from Ginseng, have neuroprotective and anti-depressant effect, the mechanism of action is incompletely understood. This study aims to elucidate the antidepressant mechanism of ginsenoside Rg1 (Rg1), a poorly absorbed ginsenoside, from the perspective of gut microbe to brain signaling.

METHODS

A mouse model of depression was induced by unpredictable mild stress (UMS). Behavioral and neurochemical tests were conducted to evaluate the effect and mechanism of Rg1 on depressive behavior. Non-target and target metabolomics were performed to identify the signaling metabolites underlying the antidepressant efficacy of Rg1. Gut microbial structure was analyzed by 16S rRNA sequencing and the potential functional strains associated with Rg1 action were investigated by in vitro bacterial culture. Chemical intervention was used to explore the mechanism of Rg1 and signaling metabolite.

RESULTS

Rg1 improved UMS-induced despair, anxiety-like and social avoidance behaviors in mice, which were accompanied by increased hypothalamic oxytocin secretion and restored neural proliferation in the hippocampus. Metabolomic analysis of the gut-brain axis revealed that Rg1 increased the concentration of serum and brain indole-3-acetic acid (IAA), a bacterial metabolite that was partially attributed to the enrichment of Lactobacillus murinus in the gut microbiome. Oral supplementation of IAA mimicked the anti-depressant action of Rg1, while oxytocin receptor antagonist abrogated the anti-depressant effects of both Rg1 and IAA.

CONCLUSION

Our work provides a new gut-to-brain signaling mechanism for the antidepressant effects of Rg1. In particular, Rg1 enriches the abundance of Lactobacillus murinus, which in turn increases the level of brain IAA and potentiates hypothalamic oxytocin signal. These findings suggest a promising pathway for producing antidepressant effects through gut-brain crosstalk.

Daily dynamics of feeling loved by parents and their prospective implications for adolescent flourishing

Feeling loved by one's caregiver is essential for individual flourishing (i.e., high levels of psychological well-being in multiple dimensions). Although similar constructs are found to benefit adolescent well-being, research that directly tests parental love as a feeling from the recipient's perspective is rare. Historically, parental love has been measured using single-assessment methods and assumed to be a stable, trait-like characteristic; yet, like any feeling, it may fluctuate in meaningful ways on a day-to-day basis-the implications of which are unknown. Using a sample of 150 adolescents (59.3% female; ages 14-16), this study estimated level (person's mean level across days) and instability (fluctuations across days) of feeling loved by a caregiver across 21 days for each adolescent, and then examined their prospective effects on adolescent flourishing 1 year later. After controlling for demographics (adolescent age, gender, family income, and parent's sex) and variable baseline levels, feeling more loved by one's caregiver in daily life significantly predicted higher levels of flourishing in two global measures 1 year later. Moreover, level and instability of feeling loved by one's caregiver played different roles for different dimensions of flourishing: higher levels significantly predicted higher levels of autonomy, purpose in life, and personal growth, whereas higher instability significantly predicted lower levels of positive relations with others and environmental mastery. Findings emphasized the importance of considering daily dynamics of feeling loved by one's caregiver and demonstrated that level (of feeling loved) is particularly important for intrapersonal aspects while instability is particularly important for interpersonal aspects of flourishing. RESEARCH HIGHLIGHTS: Adolescents feeling more loved by their caregiver in daily life had higher levels of overall flourishing 1 year later. Level (of feeling loved) is particularly important for intrapersonal aspects of adolescent flourishing, including autonomy, purpose in life, and personal growth. Stability (of feeling loved) is particularly important for interpersonal aspects of adolescent flourishing, including positive relations with others and environmental mastery.

Breastfeeding patterns in infants are associated with a later diagnosis of autism Spectrum disorder

Breastfeeding is associated with medical and developmental benefits. This study aimed to assess associations between nutritional patterns in the first year of life and the likelihood of autism spectrum disorder (ASD). 270 children diagnosed with ASD (cases) and 500 neurotypical children (controls) matched to cases by sex, ethnicity, and birth date (± 3 months) were included in this retrospective case-control study. Both groups were ascertained from children born between 2014 and 2017 whose development/nutrition were monitored at mother-child health clinics in southern Israel. Conditional logistic regression was used to determine the independent association of nutritional patterns with ASD while adjusting for socio-demographic and clinical characteristics. Both exclusive and partial breastfeeding modes were associated with decreased odds of ASD diagnosis (aOR = 0.221, 95%CI = 0.136-0.360; aOR = 0.494, 95%CI = 0.328-0.743, respectively). A breastfeeding duration of >12 months was associated with lower ASD odds (aOR = 0.418, 95%CI = 0.204-0.855), while the introduction of solids after 6 months of age was associated with higher ASD odds than the introduction of solids at 6 months (aOR = 2.455, 95%CI = 1.116-4.201). These findings suggest that a longer period of exclusive breastfeeding is associated with a subsequent reduced likelihood of ASD diagnosis, thus reiterating the importance of proper post-natal nutrition for infant neurodevelopment.

The Effect of Peer Relationships on Adolescent Loneliness: The Role of Psychological Resilience and the OXTR Gene

Background

Based on the gene-environment interaction paradigm, this study explored the effect of peer relationships on adolescent loneliness and the role of psychological resilience and the oxytocin receptor gene (OXTR).

Methods

A survey was conducted in a sample of 619 adolescents, and their oral cells were collected for DNA extraction and genotyping.

Results

The results showed that (1) both peer relationships and psychological resilience significantly affected adolescent loneliness; (2) psychological resilience partially mediated the relationship between peer relationships and loneliness in adolescents; (3) OXTR gene rs53576 polymorphism moderated both the first and second half of the indirect pathway of the mediation model. Specifically, carriers of the rs53576 polymorphism A/A genotype showed a significantly enhanced effect of peer relationships on adolescent psychological resilience, while carriers of the rs53576 polymorphism G/G genotype showed a significantly enhanced effect of psychological resilience on adolescent loneliness.

Conclusion

These findings helped elucidate the developmental mechanisms of adolescent loneliness in terms of peer relationships, psychological resilience, and OXTR gene polymorphisms.

Linking childhood trauma to the psychopathology of schizophrenia: the role of oxytocin

Childhood trauma has been linked to schizophrenia, but underlying biological mechanisms remain elusive. This study explored the potential role of plasma oxytocin as a mediator in the relationship between childhood trauma and the psychopathology of schizophrenia. 160 patients with schizophrenia and 80 age- and sex-matched healthy controls were assessed for childhood trauma experiences using the Childhood Trauma Questionnaire and structured interviews. Psychopathology was evaluated using the Positive and Negative Syndrome Scale and plasma oxytocin levels were measured. Results showed that patients with schizophrenia had lower oxytocin levels and higher childhood trauma scores than healthy controls. There was a significant correlation between childhood trauma scores and psychopathology, with plasma oxytocin levels being inversely associated with psychopathology, except for positive symptoms. Hierarchical regression analysis indicated that both childhood trauma scores and plasma oxytocin levels significantly predicted psychopathology. Plasma oxytocin levels partially mediated the relationship between childhood trauma and schizophrenia psychopathology. This study underscores the potential role of oxytocin in bridging the gap between childhood trauma and schizophrenia.

Artemisinin reduces PTSD-like symptoms, improves synaptic plasticity, and inhibits apoptosis in rats subjected to single prolonged stress

Post-Traumatic Stress Disorder (PTSD) is a chronic mental disorder characterized by symptoms of panic and anxiety, depression, impaired cognitive functioning, and difficulty in social interactions. While the effect of the traditional Chinese medicine artemisinin (AR) on PTSD is unknown, its therapeutic benefits have been demonstrated by studies on models of multiple neurological disorders. This study aimed to extend such findings by investigating the effects of AR administration on a rat model of PTSD induced by a regimen of single prolonged stress (SPS). After rats were subjected to the SPS protocol, AR was administered and its impact on PTSD-like behaviors was evaluated. In the present study, rats were subjected to a multitude of behavioral tests to evaluate behaviors related to anxiety, memory function, and social interactions. The expression of hippocampal synaptic plasticity-related proteins was detected using Western blot and immunofluorescence. The ultrastructure of synapses was observed under transmission electron microscopy. The apoptosis of hippocampal neurons was examined with Western blot, TUNEL staining, and HE staining. The results showed that AR administration alleviated the PTSD-like phenotypes in SPS rats, including behavior indicative of anxiety, cognitive deficits, and diminished sociability. AR administration was further observed to improve synaptic plasticity and inhibit neuronal apoptosis in SPS rats. These findings suggest that administering AR after the onset of severe traumatic events may alleviate anxiety, cognitive deficits, and impaired social interaction, improve synaptic plasticity, and diminish neuronal apoptosis. Hence, the present study provides evidence for AR's potential as a multi-target agent in the treatment of PTSD.

Therapeutic uses of oxytocin in stress-related neuropsychiatric disorders

Oxytocin (OXT), produced and secreted in the paraventricular nucleus and supraoptic nucleus of magnocellular and parvocellular neurons. The diverse presence and activity of oxytocin suggests a potential for this neuropeptide in the pathogenesis and treatment of stress-related neuropsychiatric disorders (anxiety, depression and post-traumatic stress disorder (PTSD)). For a more comprehensive understanding of the mechanism of OXT's anti-stress action, the signaling cascade of OXT binding to targeting stress were summarized. Then the advance of OXT treatment in depression, anxiety, PTSD and the major projection region of OXT neuron were discussed. Further, the efficacy of endogenous and exogenous OXT in stress responses were highlighted in this review. To augment the level of OXT in stress-related neuropsychiatric disorders, current biological strategies were summarized to shed a light on the treatment of stress-induced psychiatric disorders. We also conclude some of the major puzzles in the therapeutic uses of OXT in stress-related neuropsychiatric disorders. Although some questions remain to be resolved, OXT has an enormous potential therapeutic use as a hormone that regulates stress responses.

The role of the oxytocin system in the resilience of patients with breast cancer

Breast cancer is a grave traumatic experience that can profoundly compromise patients' psychological resilience, impacting their overall quality of life. The oxytocin system represents one of the essential neurobiological bases of psychological resilience and plays a critical role in regulating resilience in response to social or traumatic events during adulthood. Oxytocin, through its direct interaction with peripheral or central oxytocin receptors, has been found to have a significant impact on regulating social behavior. However, the precise mechanism by which the activation of peripheral oxytocin receptors leads to improved social is still not completely comprehended and requires additional research. Its activation can modulate psychological resilience by influencing estrogen and its receptors, the hypothalamic-pituitary-adrenal axis, thyroid function, 5-hydroxytryptamine metabolism levels, and arginine pressure release in breast cancer patients. Various interventions, including psychotherapy and behavioral measures, have been employed to improve the psychological resilience of breast cancer patients. The potential effectiveness of such interventions may be underpinned by their ability to modulate oxytocin release levels. This review provides an overview of the oxytocin system and resilience in breast cancer patients and identifies possible future research directions and interventions.

Prenatal Stress Induces Long-Term Behavioral Sex-Dependent Changes in Rats Offspring: the Role of the HPA Axis and Epigenetics

Preclinical genetic studies have related stress early exposures with changes in gene regulatory mechanisms, including epigenetic alterations, such as modifications of DNA methylation, histone deacetylation, and histones acetylation. This study evaluates the effects of prenatal stress on the behavior, hypothalamus-pituitary-adrenal (HPA)-axis, and epigenetic parameters in stressed dams and their offspring. The rats were subjected to a protocol of chronic unpredictable mild stress on the fourteenth day of pregnancy until the birth of offspring. After birth, maternal care was evaluated for six days. Following weaning, the locomotor and depressive-like behaviors of the dams and their offspring (60 days old) were assessed. The HPA axis parameters were evaluated in serum from dams and offspring, and epigenetic parameters (histone acetyltransferase (HAT), histone deacetylase (HDAC), DNA methyltransferase (DNMT) activities, and the levels of histone H3 acetylated at lysine residue 9 (H3K9ac) and histone 3 acetylated at lysine residue 14 (H3K14ac)) were assessed in dams' and offspring' brains. Prenatal stress did not significantly influence maternal care; however, it induced manic behavior in female offspring. These behavioral alterations in the offspring were accompanied by hyperactivity of the HPA-axis, epigenetic adaptations in the activity of HDAC and DNMT, and acetylation in the histones H3K9 and H3K14. In addition, the prenatal stressed female offspring showed increased levels of ACTH compared to their male counterpart. Our findings reinforce the impact of prenatal stress on behavior, stress response, and epigenetic profile of offspring.

The evolved nest, oxytocin functioning, and prosocial development

Prosociality, orientation to attuned, empathic relationships, is built from the ground up, through supportive care in early life that fosters healthy neurobiological structures that shape behavior. Numerous social and environmental factors within early life have been identified as critical variables influencing child physiological and psychological outcomes indicating a growing need to synthesize which factors are the most influential. To address this gap, we examined the influence of early life experiences according to the evolved developmental niche or evolved nest and its influence on child neurobiological and sociomoral outcomes, specifically, the oxytocinergic system and prosociality, respectively. To-date, this is the first review to utilize the evolved nest framework as an investigatory lens to probe connections between early life experience and child neurobiological and sociomoral outcomes. The evolved nest is comprised of characteristics over 30 million years old and is organized to meet a child's basic needs as they mature. Converging evidence indicates that humanity's evolved nest meets the needs of a rapidly developing brain, optimizing normal development. The evolved nest for young children includes soothing perinatal experiences, breastfeeding, positive touch, responsive care, multiple allomothers, self-directed play, social embeddedness, and nature immersion. We examined what is known about the effects of each evolved nest component on oxytocinergic functioning, a critical neurobiological building block for pro-sociomorality. We also examined the effects of the evolved nest on prosociality generally. We reviewed empirical studies from human and animal research, meta-analyses and theoretical articles. The review suggests that evolved nest components influence oxytocinergic functioning in parents and children and help form the foundations for prosociality. Future research and policy should consider the importance of the first years of life in programming the neuroendocrine system that undergirds wellbeing and prosociality. Complex, interaction effects among evolved nest components as well as among physiological and sociomoral processes need to be studied. The most sensible framework for examining what builds and enhances prosociality may be the millions-year-old evolved nest.

Resilience and Attachment in Patients with Major Depressive Disorder and Bipolar Disorder

BACKGROUND

Resilience represents one of the fundamental elements of attachment and has often been investigated in mood disorders. This study aims to investigate possible correlations between attachment and resilience in patients with major depressive disorder (MDD) and bipolar disorder (BD).

METHODS

106 patients (51 MDD, 55 BD) and 60 healthy controls (HCs) were administered the 21-item Hamilton Depression Rating Scale (HAM-D-21), the Hamilton Anxiety Rating Scale (HAM-A), the Young Mania Rating Scale (YMRS), the Snaith-Hamilton Pleasure Scale (SHAPS), the Barratt Impulsiveness Scale-11 (BIS-11), the Toronto Alexithymia Scale (TAS), the Connor-Davidson Resilience Scale (CD-RISC), and Experiences in Close Relationship (ECR).

RESULTS

MDD and BD patients did not significantly differ from each other according to the HAM-D-21, HAM-A, YMRS, SHAPS, and TAS, while they scored higher than HCs on all these scales. Patients in the clinical group scored significantly lower on CD-RISC resilience than HCs (p < 0.01). A lower proportion of secure attachment was found among patients with MDD (27.4%) and BD (18.2%) compared to HCs (90%). In both clinical groups, fearful attachment prevailed (39.2% patients with MDD; 60% BD).

CONCLUSIONS

Our results highlight the central role played by early life experiences and attachment in participants with mood disorders. Our study confirms the data from previous research showing a significant positive correlation between the quality of attachment and the development of resilience capacity, and supports the hypothesis that attachment constitutes a fundamental aspect of resilience capacity.

Resilience by design: How nature, nurture, environment, and microbiome mitigate stress and allostatic load

Resilience to psychological stress is defined as adaption to challenging life experiences and not the absence of adverse life events. Determinants of resilience include personality traits, genetic/epigenetic modifications of genes involved in the stress response, cognitive and behavioral flexibility, secure attachment with a caregiver, social and community support systems, nutrition and exercise, and alignment of circadian rhythm to the natural light/dark cycle. Therefore, resilience is a dynamic and flexible process that continually evolves by the intersection of different domains in human’s life; biological, social, and psychological. The objective of this minireview is to summarize the existing knowledge about the multitude factors and molecular alterations that result from resilience to stress response. Given the multiple contributing factors in building resilience, we set out a goal to identify which factors were most supportive of a causal role by the current literature. We focused on resilience-related molecular alterations resulting from mind-body homeostasis in connection with psychosocial and environmental factors. We conclude that there is no one causal factor that differentiates a resilient person from a vulnerable one. Instead, building resilience requires an intricate network of positive experiences and a healthy lifestyle that contribute to a balanced mind-body connection. Therefore, a holistic approach must be adopted in future research on stress response to address the multiple elements that promote resilience and prevent illnesses and psychopathology related to stress allostatic load.

Biological Correlates of Post-Traumatic Growth (PTG): A Literature Review

Since the beginning of medical science, much research have focused on the psychopathological effects of traumatic experiences. Despite in past centuries the scientific literature on mental health has been mainly focused on the harmful effects of traumatic occurrences, more recently the idea of "post-traumatic growth" emerged, on the basis of a growing interest in the characteristics of resilience and possible positive consequences of trauma. In this framework, increasing attention is now being paid to the psychological meaning of PTG, with a consistent number of psychopathological and epidemiological studies on this subject, but limited literature focused on neurobiological correlates or eventual biomarkers of this condition. The present work aimed to summarize and review the available evidence on neurobiological correlates of PTG and their psychological and clinical meaning. Results highlighted a variety of biochemical and neurobiological differences between PTG and non-PTG individuals, partially corroborating findings from earlier research on post-traumatic stress disorder (PTSD). However, although promising, findings in this field are still too limited and additional studies on the neurobiological correlates of traumatic experiences are needed in order to gain a better understanding of the subject.

Association between exclusive breastfeeding and postpartum post-traumatic stress disorder

BACKGROUND

Research on the association between breastfeeding and postpartum post-traumatic stress disorder (PTSD) is sparse. This study aimed to examine the association between exclusive breastfeeding up to 42 days after childbirth and postpartum PTSD.

METHODS

An epidemiologic study was conducted in a tertiary hospital in China between October 2019 and October 2020. Eligible mothers were recruited at 3 days after childbirth and assessed using the Post-Traumatic Stress Disorder Checklist - Civilian version (PCL-C) for PTSD at 42 days postpartum. The independent association between exclusive breastfeeding up to 42 days after childbirth and postpartum PTSD was estimated using log-binomial regression models, after adjusting for potential confounders.

RESULTS

Ninety-two of 759 (12.1%) mothers developed postpartum PTSD within 42 days after childbirth. Compared with partially breastfeeding mothers, exclusively breastfeeding mothers had lower risks of postpartum PTSD (relative risk [RR] 0.28; 95% confidence interval [CI] 0.13, 0.59), re-experience (RR 0.48; 95% CI 0.30, 0.76), avoidance (RR 0.55; 95% CI 0.32, 0.97), and hyperarousal (RR 0.52; 95% CI 0.34, 0.78). After adjustment for family support, parity, mode of delivery, perceived birth trauma, early contact / suckling, and rooming-in, associations between exclusive breastfeeding and postpartum PTSD remained significant: the overall PTSD adjusted relative risk [aRR] was 0.31; (95% CI 0.15, 0.66), with a re-experience aRR of 0.48; (95% CI 0.30, 0.77) and hyperarousal aRR of 0.56; (95% CI 0.37, 0.85).

CONCLUSION

Exclusive breastfeeding up to 42 days after childbirth was associated with reduced risk of postpartum PTSD. While the potential for reverse causation cannot be ruled out, strategies to improve rates of exclusive breastfeeding through teaching, counselling, and support may benefit mothers and their infants by reducing the risk of postpartum PTSD.

Interactions between the κ opioid system, corticotropin-releasing hormone and oxytocin in partner loss

Selective adult social attachments, or ‘pair bonds’, represent central relationships for individuals in a number of social species, including humans. Loss of a pair mate has emotional consequences that may or may not diminish over time, and that often translate into impaired psychological and physical health. In this paper, we review the literature on the neuroendocrine mechanisms for the emotional consequences of partner loss, with a special focus on hypothesized interactions between oxytocin, corticotropin-releasing hormone and the κ opioid system.

This article is part of the theme issue ‘Interplays between oxytocin and other neuromodulators in shaping complex social behaviours’.

Birth, love, and fear: Physiological networks from pregnancy to parenthood

Pregnancy and childbirth are among the most dramatic physiological and emotional transformations of a lifetime. Despite their central importance to human survival, many gaps remain in our understanding of the temporal progression of and mechanisms underlying the transition to new parenthood. The goal of this paper is to outline the physiological and emotional development of the maternal-infant dyad from late pregnancy to the postpartum period, and to provide a framework to investigate this development using non-invasive timeseries. We focus on the interaction among neuroendocrine, emotional, and autonomic outputs in the context of late pregnancy, parturition, and post-partum. We then propose that coupled dynamics in these outputs can be leveraged to map both physiologic and pathologic pregnancy, parturition, and parenthood. This approach could address gaps in our knowledge and enable early detection or prediction of problems, with both personalized depth and broad population scale.

Peripheral oxytocin concentrations in psychiatric disorders - A systematic review and methanalysis: Further evidence

Increased interest in understanding how changes in the oxytocinergic system are associated with the etiology and progression of psychiatric disorders has currently boosted the publication of studies. We present a systematic literature review followed by meta-analyses assessing whether peripheral oxytocin (OXT) levels among psychiatric patients differ from healthy controls, considering the moderating role of methodological aspects and samples' characteristics. The following electronic databases were searched: PubMed, Web of Science, PsycINFO, SciELO, LILACS, and Scopus. Fifty-five papers were included in the analysis, and nine independent meta-analyses were performed according to the different diagnoses. Lower OXT concentrations were found in groups of specific disorders (i.e., schizophrenia, restricting and binge-eating/purging subtypes of anorexia nervosa, and borderline personality disorder) with medium to large effect sizes. Great heterogeneity was found among the studies, so that caution is needed to interpret the results. High OXT levels with an effect size of the same magnitude were found for bipolar disorder - type I and obsessive disorder. In contrast, no differences were found for bulimia, autism spectrum, depression, or social anxiety. No meta-analyses were performed for body dysmorphic disorder, post-traumatic stress disorder, or trichotillomania because only one study was identified for each of these disorders. Altered endogenous OXT concentrations are found in several disorders addressed and must be analyzed according to each disorder's specificities.

Oxytocin Prevents the Development of 3-NP-Induced Anxiety and Depression in Male and Female Rats: Possible Interaction of OXTR and mGluR2

Huntington disease (HD) is a progressive neurological disorder with dominant motor symptoms. It also has psychiatric manifestations, like anxiety and depression, that can emerge themselves before motor symptoms and impose a major burden on patients. Oxytocin (OXT) is a newly emerged treatment for disorders like autism and schizophrenia and recently is using to alleviate depression and anxiety. In the current study, we investigated the behavioral and molecular effects of OXT on the development of anxiety and depression in 3-nitropropionic acid (3-NP)-induced model of HD. Anxiety- and depression-like behaviors as well as the levels of oxytocin receptor (OXTR), metabotropic glutamate receptor (mGluR) 2, mGluR5, and glutathione (GSH) were measured in striatum, hippocampus, prefrontal cortex, and amygdala. Also, we questioned if sex had any modulatory effect. We found that 3-NP increased anxiety and depression compared to controls. It also reduced the levels of OXTR and mGluR2, increased mGluR5, and reduced GSH in studied brain regions. Pretreatment with OXT before the injection of 3-NP ameliorated anxiety and depression. Additionally, it protected the brain from developing low levels of OXTR, mGluR2, and GSH and high levels of mGluR5 in studied regions. The protective effects of OXT were similar between male and female animals. These data suggest that OXTR, mGluR2, mGluR5, and GSH may contribute to psychiatric manifestations of HD. In addition, pretreatment with OXT could prevent the mood changes in male and female rats.

Salivary oxytocin in autistic patients and in patients with intellectual disability

BACKGROUND

Assessing the role of oxytocin (OT) in the regulation of social interaction is a promising area that opens up new opportunities for studying the mechanisms of developing autism spectrum disorders (ASD).

AIM

To assess the correlation between the salivary OT level and age-related and psychopathological symptoms of children with intellectual disability (ID) and ASD.

METHODS

We used the clinical and psychopathological method to assess the signs of ASD based on International Classification of Diseases (ICD-10), the severity of ASD was specified by the selected Russian type version "Childhood Autism Rating Scale" (CARS). Patients of both groups had an IQ score below 70 points.

RESULTS

The median and interquartile range of salivary OT levels in patients with ID and ASD were 23.897 [14.260-59.643] pg/mL, and in the group ID without ASD - Me = 50.896 [33.502-83.774] pg/mL (p = 0.001). The severity of ASD on the CARS scale Me = 51.5 [40.75-56.0] score in the group ID with ASD, and in the group ID without ASD-at the level of Me = 32 [27.0-38.0] points (p < 0.001). According to the results of correlation-regression analysis in the main group, a direct correlation was established between salivary OT level and a high degree of severity of ASD Rho = 0.435 (p = 0.005). There was no correlation between the salivary OT level and intellectual development in the group ID with ASD, Rho = 0.013 (p = 0.941) and we have found a relationship between oxytocin and intellectual development in the group ID without ASD, Rho = 0.297 (p = 0.005). There was no correlation between salivary OT and age, ASD and age.

CONCLUSION

The results of this study indicate that patients in the group ID with ASD demonstrated a lower level of salivary OT concentration and a direct relationship between the maximum values of this indicator and the severity of autistic disorders, in contrast to patients in the group ID without ASD.

The Molecular Basis of Resilience: A Narrative Review

Resilience refers to the adaptability of a person - an ability to "bounce-back" from stressors. We question if resilience can be strengthened, potentially to decrease the risk of stress-related disorders. Unfortunately, the molecular origins of resilience are complicated and not yet well understood. In this review, we examine the various physiological biomarkers of resilience, including the associated genes, epigenetic changes, and protein biomarkers associated with resilient phenotypes. In addition to assessing biomarkers that may indicate higher levels of resilience, we also review at length the many biomarkers that confer lower levels of resilience and may lead to disorders of low resilience, such as anxiety and depression. This large and encompassing review may help to identify the possible therapeutic targets of resilience. Hopefully these studies will lead to a future where stress-related disorders can be prevented, rather than treated.

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.

Association of Breastfeeding for the First Six Months of Life and Autism Spectrum Disorders: A National Multi-Center Study in China

Previous studies have shown that exclusive breastfeeding is associated with lower odds of having autism spectrum disorders (ASD) in children, but data are lacking in Asian countries, especially China. This cross-sectional study of seven cities in China collected data from August 2016 to March 2017 from 6049 toddlers aged 16-30 months and their parents who responded to questionnaires. The breastfeeding status was collected via questionnaires based on recommendations from the World Health Organization. The standard procedure for screening and diagnosis was applied to identify toddlers with ASD. Among the 6049 toddlers (3364 boys [55.6%]; mean [SD] age, 22.7 [4.1] months), 71 toddlers (1.2%) were identified as ASD. The prevalence of exclusive breastfeeding, partial breastfeeding, and not breastfeeding was 48.8%, 42.2%, and 9.1%, respectively. Compared to toddlers with exclusive breastfeeding, toddlers with partial breastfeeding or without breastfeeding had higher odds of having ASD (odd ratios [OR]: 1.55, 95% confidence interval [CI]: 0.90-2.74; OR: 2.34, 95% CI: 1.10-4.82). We did not find significant modification of demographic characteristics on the associations. The results remained robust in multiple sensitivity analyses. Toddlers without breastfeeding for the first six months of life had higher odds of having ASD, and our findings shed light on the necessity of strengthening public health efforts to increase exclusive breastfeeding in China.

Early life adversity affecting the attachment bond alters ventral tegmental area transcriptomic patterning and behavior almost exclusively in female mice

Early life experiences that affect the attachment bond formation can alter developmental trajectories and result in pathological outcomes in a sex-related manner. However, the molecular basis of sex differences is quite unknown. The dopaminergic system originating from the ventral tegmental area has been proposed to be a key mediator of this process. Here we exploited a murine model of early adversity (Repeated Cross Fostering, RCF) to test how interfering with the attachment bond formation affects the VTA-related functions in a sex-specific manner. Through a comprehensive behavioral screening, within the NiH RDoC framework, and by next-generation RNA-Seq experiments, we analyzed the long-lasting effect of RCF on behavioral and transcriptional profiles related to the VTA, across two different inbred strains of mouse in both sexes. We found that RCF impacted to an extremely greater extent VTA-related behaviors in females than in males and this result mirrored the transcriptional alterations in the VTA that were almost exclusively observed in females. The sexual dimorphism was conserved across two different inbred strains in spite of their divergent long lasting consequences of RCF exposure. Our data suggest that to be female primes a sub-set of genes to respond to early environmental perturbations. This is, to the best of our knowledge, the first evidence of an almost exclusive effect of early life experiences on females, thus mirroring the extremely stronger impact of precocious aversive events reported in clinical studies in women.

Biological Connection of Psychological Stress and Polytrauma under Intensive Care: The Role of Oxytocin and Hydrogen Sulfide

This paper explored the potential mediating role of hydrogen sulfide (H2S) and the oxytocin (OT) systems in hemorrhagic shock (HS) and/or traumatic brain injury (TBI). Morbidity and mortality after trauma mainly depend on the presence of HS and/or TBI. Rapid "repayment of the O2 debt" and prevention of brain tissue hypoxia are cornerstones of the management of both HS and TBI. Restoring tissue perfusion, however, generates an ischemia/reperfusion (I/R) injury due to the formation of reactive oxygen (ROS) and nitrogen (RNS) species. Moreover, pre-existing-medical-conditions (PEMC's) can aggravate the occurrence and severity of complications after trauma. In addition to the "classic" chronic diseases (of cardiovascular or metabolic origin), there is growing awareness of psychological PEMC's, e.g., early life stress (ELS) increases the predisposition to develop post-traumatic-stress-disorder (PTSD) and trauma patients with TBI show a significantly higher incidence of PTSD than patients without TBI. In fact, ELS is known to contribute to the developmental origins of cardiovascular disease. The neurotransmitter H2S is not only essential for the neuroendocrine stress response, but is also a promising therapeutic target in the prevention of chronic diseases induced by ELS. The neuroendocrine hormone OT has fundamental importance for brain development and social behavior, and, thus, is implicated in resilience or vulnerability to traumatic events. OT and H2S have been shown to interact in physical and psychological trauma and could, thus, be therapeutic targets to mitigate the acute post-traumatic effects of chronic PEMC's. OT and H2S both share anti-inflammatory, anti-oxidant, and vasoactive properties; through the reperfusion injury salvage kinase (RISK) pathway, where their signaling mechanisms converge, they act via the regulation of nitric oxide (NO).

Harnessing the Neurobiology of Resilience to Protect the Mental Well-Being of Healthcare Workers During the COVID-19 Pandemic

Healthcare workers are at a high risk of psychological morbidity in the face of the COVID-19 pandemic. However, there is significant variability in the impact of this crisis on individual healthcare workers, which can be best explained through an appreciation of the construct of resilience. Broadly speaking, resilience refers to the ability to successfully adapt to stressful or traumatic events, and thus plays a key role in determining mental health outcomes following exposure to such events. A proper understanding of resilience is vital in enabling a shift from a reactive to a proactive approach for protecting and promoting the mental well-being of healthcare workers. Research in the past decade has identified six areas that provide promising leads in understanding the biological basis of individual variations in resilience. These are: (1) the key role played by the monoamines noradrenaline and serotonin, (2) the centrality of the hypothalamic-pituitary-adrenal axis in influencing stress vulnerability and resilience, (3) the intimate links between the immune system and stress sensitivity, (4) the role of epigenetic modulation of gene expression in influencing the stress response, (5) the role played by certain neuropeptides as a natural “brake” mechanism in the face of stress, and (6) the neurobiological mechanisms by which environmental factors, such as exercise, diet, and social support, influence resilience to subsequent life events. Though much of this research is still in its early stages, it has already provided valuable information on which strategies – including dietary changes, lifestyle modification, environmental modification, psychosocial interventions, and even pharmacological treatments – may prove to be useful in fostering resilience in individuals and groups. This paper examines the above evidence more closely, with a specific focus on the challenges faced by healthcare workers during the COVID-19 pandemic, and provides suggestions regarding how it may be translated into real-world interventions, as well as how the more tentative hypotheses advanced in this field may be tested during this critical period.