The role of oxytocin in social bonding, stress regulation and mental health: an update on the moderating effects of context and interindividual differences

Diurnal changes of salivary oxytocin in healthy and psychiatric adolescents

Oxytocin, a neuropeptide with implications for interpersonal relationships and psychopathology, remains relatively unexplored in adolescence, particularly in acute mental health states. While studies examined baseline levels and reactivity patterns in salivary oxytocin, no study has tested diurnal patterns of oxytocin in the context of youth mental health. The current study examines diurnal rhythms of salivary oxytocin in 34 adolescent patients admitted to a psychiatric inpatient ward, as compared to 33 healthy peers. Samples were collected at four daily time-points across two consecutive days (8 a.m., 12 p.m., 4 p.m., 8 p.m.). Patients underwent psychiatric assessments and completed self-report questionnaires prior to the study and again at discharge. Results revealed significant differences between patients and healthy controls, indicating elevated overall salivary oxytocin production in the patient group. No significant differences were found among patients at the admission and discharge sampling. A consistent diurnal pattern emerged across participants that showed oxytocin elevation toward evening. Diurnal oxytocin levels correlated with measures of emotion regulation and anxiety. Findings are the first to describe the diurnal rhythms of oxytocin in youth and suggest that diurnal oxytocin may serve as additional biomarker of psychopathology. Future research is needed to assess processes that may lead to change in patients' diurnal oxytocin patterns.

Oxytocin does not impact forced-choice recognition memory in an experimental trauma film paradigm with healthy women

Introduction

Traumatic experiences are thought to alter memory acquisition and consolidation. Cognitive models of PTSD suggest that voluntary and involuntary memories after trauma can be independently addressed through interventions. The administration of oxytocin before exposure to a trauma film led to more intrusive (involuntary) memories than placebo. The effect of oxytocin on voluntary memory of the traumatic film, however, remains unclear. The current study aimed to assess whether intranasal oxytocin administration facilitates forced-choice recognition memory after a trauma film paradigm.

Material & methods

We performed a pooled analysis of two randomized, double-blind, placebo-controlled studies (N = 437) to assess the impact of intranasal oxytocin administration on declarative memory. Participants received 24 I.U. of oxytocin, either 40 minutes before a trauma film paradigm or immediately afterward. We applied a forced-choice recognition task seven days after the trauma film paradigm. The task comprised pre-, peri, and post-trauma film scene details.

Results

The administration of oxytocin did not affect recognition performance for any film scene (F(2, 401) = .49, p = .61). Participants remembered significantly more peri-traumatic film details compared to pre- and post-trauma details (F(1.72, 802) = 103.38, p <.001).

Discussion

Although the exogenous oxytocin administration before a trauma film has been shown to influence the acquisition of intrusive memories, it does not seem to affect the recognition memory of trauma film details. That aligns with cognitive models of PTSD, suggesting that voluntary and involuntary memory after trauma can be independently addressed through experimental interventions.

Multi-dimensional social relationships shape social attention in monkeys

Social relationships guide individual behavior and ultimately shape the fabric of society. Primates exhibit particularly complex, differentiated, and multidimensional social relationships, which form interwoven social networks, reflecting both individual social tendencies and specific dyadic interactions. How the patterns of behavior that underlie these social relationships emerge from moment-to-moment patterns of social information processing remains unclear. Here, we assess social relationships among a group of four monkeys, focusing on aggression, grooming, and proximity. We show that individual differences in social attention vary with individual differences in patterns of general social tendencies and patterns of individual engagement with specific partners. Oxytocin administration altered social attention and its relationship to both social tendencies and dyadic relationships, particularly grooming and aggression. Our findings link the dynamics of visual information sampling to the dynamics of primate social networks.

Physiological welfare indicators in wild cetaceans: Epidermal cortisol and oxytocin concentrations in stranded striped dolphins

Anthropogenic pressures and climate change present growing challenges for cetaceans, as the combined effects of multiple stressors can jeopardize their welfare and survival. In this context, validating reliable individual welfare indicators is crucial for quantifying these impacts. This study aimed to validate a method for measuring cortisol and oxytocin from the epidermis of stranded striped dolphins (Stenella caeruleoalba) using enzyme immunoassays, while accounting for confounding factors such as epidermal layer and body location. The effects of different causes of death-'Peracute Underwater Entrapment' and 'Distress Associated'- along with biological factors, were examined in relation to epidermal hormone levels. Furthermore, the relationship between these hormone levels and markers suggesting an impaired welfare, was explored. Validation tests indicated that the method was effective in quantifying both epidermal cortisol and oxytocin concentrations. Specifically, epidermal cortisol levels showed strong correlations with both serum and blubber levels and were 6 times higher in emaciated individuals and 14 times higher in those with distress-associated deaths, supporting its use in assessing hypothalamic-pituitary-adrenal activity. Interestingly, results supported the validity of epidermal cortisol levels as markers of impaired welfare in dolphins, as they consistently increased across conditions assumed to negatively affect welfare but varying in terms of severity and duration. In contrast, epidermal oxytocin levels could not be validated as an indicator of the general oxytocin system nor as an indicator of welfare in this species. In conclusion, this study successfully validated epidermal cortisol as a reliable physiological indicator of welfare in striped dolphins, providing a promising tool for assessing individual and population-level welfare impacts. However, further research is needed to fully explore the potential role of oxytocin as a welfare biomarker in cetaceans.

The Impact of Oxytocin on Stimulus Discrimination of Zebrafish Albino and Non-Albino Models

Zebrafish have the ability, to a certain extent, to distinguish between different types of stimuli, including distinguishing between videos of conspecifics and non-conspecifics, a skill known as stimulus discrimination. In this study, we investigated the effects of oxytocin on this ability in albino and non-albino zebrafish models, focusing on the correlations between albinism, sensory deficiencies, and socio-emotional behaviors. Our hypothesis is based on the premise that oxytocin influences socio-emotional behaviors in zebrafish, with varying effects depending on phenotype (albino vs. non-albino), social context, and treatment duration. Studies have shown that albino zebrafish have more pronounced sensory deficiencies, meaning they may benefit more from oxytocin in terms of increased social comfort and interactions with conspecifics, while non-albino zebrafish would experience a reduction in defensive behaviors and anxiety. To test this, two experiments were conducted: one assessing the responses to video predator stimuli and the other comparing social interactions with real and video conspecifics. The results showed significant differences between the two groups: non-albino zebrafish exhibited stronger long-term reductions in anxiety-related behaviors, such as reaction speed and freezing, suggesting that oxytocin regulates defensive responses and aggression. Meanwhile, albino zebrafish showed greater improvements in social interactions, reflecting the nuanced, phenotype-dependent effects of oxytocin. These results not only confirm existing research but also highlight the therapeutic potential of oxytocin in treating socio-emotional deficiencies.

Investigating the psychophysiological effects of NaiKan Therapy: salivary oxytocin and cortisol release

NaiKan Therapy, a method of self-reflection and introspection, has garnered considerable interest for its psychological benefits. However, its physiological impacts, particularly on hormonal regulation, remain underexplored. In this study, we aimed to investigate the effects of NaiKan Therapy on salivary oxytocin and cortisol release, shedding light on the psychophysiological mechanisms underlying this introspective practice. Sixty participants underwent Naikan Therapy sessions over five consecutive days, during which salivary samples were collected at multiple time points. Salivary oxytocin and cortisol levels were measured using enzyme-linked immunosorbent assay (ELISA) kits. Our results revealed significant increases in salivary oxytocin levels following NaiKan Therapy, suggesting a potential role of this practice in enhancing social bonding and emotional regulation. Conversely, salivary cortisol levels exhibited a decrease post-therapy, indicating a reduction in stress reactivity. These findings provide novel insights into the neuroendocrine mechanisms underlying NaiKan Therapy and highlight its potential as a holistic approach to improving mental wellbeing. Further research exploring the long-term effects of NaiKan Therapy and its implications for clinical practice is warranted.

Oxytocin effects on socially transmitted food preferences are moderated by familiarity between rats

RATIONALE

In the socially transmitted food preference (STFP) paradigm, rats change their preference for food rewards after socially interacting with a conspecific who has been fed with the originally non-preferred food. Here, we asked if oxytocin (OXT), a neuropeptide known for its role in social affiliation and social behavior, plays a role in STFP. Since OXT's influences on social behavior can be familiarity-dependent, we further asked if OXT effects on STFP are moderated by the familiarity between rats.

OBJECTIVES

Does OXT modulate rats' socially transmitted food choices in a familiarity-dependent way.

METHODS

We systemically injected either vehicle, low-dose (0.25 mg/kg) of OXT, or large-dose (1.0 mg/kg) of OXT before social interaction with either a familiar cagemate (in-group) or an unfamiliar conspecific from a different cage (out-group).

RESULTS

We found an intergroup bias in STFP: vehicle-treated rats showed larger socially transmitted changes in food preference in the out-group than the in-group condition. OXT modulated STFP in a familiarity-dependent way: OXT prevented the increase in the consumption of the non-preferred food in the out-group, and decreased the consumption of the preferred food in the in-group. These effects were dose-dependent and observed under acute OXT action, but also on the subsequent day when acute OXT effects dissipated, suggesting long-lasting social learning effects of OXT. Additional analyses suggest that the familiarity and dose-dependent effects of OXT on STFP cannot be attributed to OXT's anorexic actions or differences in the duration of the social interactions.

CONCLUSIONS

OXT modulates STFP in a familiarity-dependent way.

Oxytocin as a physiological correlate of dyadic music therapy relationships - a randomized crossover pilot study

Rationale

Music therapy has been in practice for years. However, the mechanism of action of music or music therapy is not well understood. It is only recently that the neuroendocrinological basis of therapeutic relationships has become the subject of growing research interest. The aim of this pilot study (Clinical Trial No: DRKS00035174) is to investigate whether oxytocin is usable and feasible as a biomarker of attachment to demonstrate the development of therapeutic alliance between therapist and patient in a dyadic music therapy setting.

Methods

In a single-measure crossover design, children aged 6-12 years from a special school for social and emotional disorders, were randomly with either music therapy followed by a waiting list control group that performed silent work, or vice versa. The respective interventions were conducted on the school premises on different days over a period of 1 month. The primary outcome was salivary oxytocin, with tests performed immediately before and after each 30-min intervention.

Results

Thirty-two children were included in the study, resulting in n = 16 children per allocation sequence. During the implementation of the study, difficulties were encountered with protocol adherence both in terms of the duration of the music therapy and the implementation of the silent work in the control group. There were no dropouts, however, only 28 children were included in the final data analysis as two participants in each group were excluded due to large fluctuations in oxytocin levels. Between-group comparison and within-group comparisons showed no significant changes in oxytocin levels. However, the music therapist showed a significant increase in oxytocin levels in the before after measurement. No side effects or adverse events were reported during the trial.

Conclusion

The findings indicated a responsiveness of oxytocin to musical stimulation. Although feasibility of oxytocin measurement was clearly demonstrated, evaluation of the results is difficult against the background of many remaining questions regarding individual and contextual factors influencing the oxytocinergic system. Moreover, the clinical significance of changes in oxytocin levels remains a topic for further research to better understand the role of oxytocin in the attachment formation between therapist and patient in music therapy.

Oxytocin Amplifies Negative Response to Ambiguity in Adolescent Females With and Without Eating Disorders

OBJECTIVE

Eating disorders (ED) typically emerge in adolescence, a critical period for brain development and peer bonding. Interpersonal difficulties-particularly social anxiety-frequently co-occur with ED. Oxytocin is a neuropeptide that modulates social cognition and linked to prosocial effects. To date, no study has investigated oxytocin's effects on negative interpretation bias toward ambiguous information in adolescents with ED.

METHODS

Forty-eight female adolescents aged 16 to 17 years with and without EDs took part in a placebo-controlled, double-blinded, randomised, crossover trial investigating the effects of 24 IU intranasal oxytocin on negative interpretations of ambiguous scenarios. Participants and controls were tested twice, approximately one week apart.

RESULTS

Contrary to hypothesis, oxytocin increased negative interpretations overall (p = 0.019, large effect). Adolescent females with AN or BN made more negative interpretations than controls when presented with ambiguous information. There was no group effect for those who reached or did not reach threshold on an autism screen.

CONCLUSIONS

This study suggests adolescents with EDs interpret ambiguous information more negatively than controls and that oxytocin administration amplifies negative responses to ambiguity in adolescent females, including in controls. Research tools that effectively identify these biases would help to widen the scope of ED treatments for adolescents.

Social pain: A systematic review on interventions

Social pain is emotional distress caused by harm or threat to social connections that results in social exclusion, rejection, or loss. Social Pain is also a potentiator of physical pain. Supportive social relationships are widely recognized for their impact on maintaining health and well-being. The Passion of Jesus Christ serves as a quintessential example of social pain (i.e., desertion, betrayal, denial) potentiating physical pain (i.e., beatings, Crown of Thorns, crucifixion). Christ opts to forgive. Although forgiveness is one solution to reduce social pain, other interventions exist. This review seeks to identify and summarize interventions associated with reducing social pain. We conducted a systematic review using Medline (PubMed), Google Scholar, and Cochrane CENTRAL to identify relevant articles. Results: The database searches produced 548 articles. Fourteen randomized controlled trials (RCTs) were included in this systematic review. Acetaminophen, both deceptive and open-label placebos, mindfulness training, and psilocybin were found to reduce social pain. Of note, the combination of acetaminophen and forgiveness yielded superior results compared to either acetaminophen or forgiveness alone. Pharmacological interventions operate on the premise that the neural pathways responsible for physical pain also play a role in social pain. Both pharmacological and non-pharmacological interventions are available for reducing social pain.

Functional significance of some common oxytocin receptor SNPs involved in complex human traits

BACKGROUND

Oxytocin function is associated with a range of human traits and is often indexed by common polymorphisms of the receptor gene OXTR. Little is known however about the functional significance of these polymorphisms.

OBJECTIVES

To examine the effects of common polymorphisms of OXTR on transcription expression in human neural cells.

METHOD

The impact of four common OXTR SNPs (rs1042778, rs4686302, rs2254298 and rs237887) on OXTR gene expression were tested in human neuroblastoma cell line, SH-SY5Y, a commonly used cell line for neurological disease. SNPs were chosen as having robust evidence for associations with complex human traits after consideration of linkage patterns across OXTR.

RESULTS

The expression level of GG genotype of rs1042778 was significantly lower than TT genotypes. None of the other SNPs were related to functional transcription.

CONCLUSIONS

OXTR polymorphisms showing robust associations with complex human traits are not reliably associated with changes in transcription of OXTR. Increasing cooperation between behavioral and biological scientists is needed to bridge the gap between human trait and functional biological studies to improve our understanding of oxytocin and other important mammalian neuroendocrine processes.

DNA Methylation in Alzheimer's Disease

To date, DNA methylation is the best characterized epigenetic modification in Alzheimer's disease. Involving the addition of a methyl group to the fifth carbon of the cytosine pyrimidine base, DNA methylation is generally thought to be associated with the silencing of gene expression. It has been hypothesized that epigenetics may mediate the interaction between genes and the environment in the manifestation of Alzheimer's disease, and therefore studies investigating DNA methylation could elucidate novel disease mechanisms. This chapter comprehensively reviews epigenomic studies, undertaken in human brain tissue and purified brain cell types, focusing on global methylation levels, candidate genes, epigenome wide approaches, and recent meta-analyses. We discuss key differentially methylated genes and pathways that have been highlighted to date, with a discussion on how new technologies and the integration of multiomic data may further advance the field.

MDMA and MDMA-Assisted Therapy

MDMA (i.e., 3,4-methylenedixoymethamphetamine), commonly known as "Ecstasy" or "Molly," has been used since the 1970s both in recreational and therapeutic settings. The Food and Drug Administration (FDA) designated MDMA-Assisted Therapy (MDMA-AT) as a Breakthrough Therapy for posttraumatic stress disorder (PTSD) in 2017, and the FDA is requiring an additional phase 3 trial after rejecting the initial New Drug Application in 2024. Unlike other psychedelics, MDMA uniquely induces prosocial subjective effects of heightened trust and self-compassion while maintaining ego functioning as well as cognitive and perceptual lucidity. While recreational use in nonmedical settings may still cause harm, especially due to adulterants or when used without proper precautions, conclusions that can be drawn from studies of recreational use are limited by many confounds. This especially limits the extent to which evidence related to recreational use can be extrapolated to therapeutic use. A considerable body of preliminary evidence suggests that MDMA-AT delivered in a controlled clinical setting is a safe and efficacious treatment for PTSD. After a course of MDMA-AT involving three MDMA administrations supported by psychotherapy, 67%-71% of individuals with PTSD no longer meet diagnostic criteria after MDMA-AT versus 32%-48% with placebo-assisted therapy, and effects endure at long-term follow-up. This review primarily aims to distinguish evidence of recreational use in nonclinical settings versus MDMA-AT using pharmaceutical-grade MDMA in controlled clinical settings. This review further describes the putative neurobiological mechanisms of MDMA underlying its therapeutic effects, the clinical evidence of MDMA-AT, considerations at the level of public health and policy, and future research directions.

Trauma-Informed Strategies in Pediatric Primary Care

Child trauma, particularly within the context of the caregiving relationship, can have profound impacts on health, thus pediatric clinicians have a crucial role in recognizing and responding to trauma. Yet, trauma-informed care (TIC) is often described by its guiding principles rather than an approach to implementation. TIC requires the pediatric clinician to not only be familiar with the physiology of trauma, but actively promote resilience and employ strategies for primary prevention, secondary response and tertiary treatment of trauma. This study covers practical approaches to care that allow for promoting resilience, and the recognition, diagnosis and management of trauma.

Oxytocin Protects Against Corticosterone-Induced DA Dysfunction: An Involvement of the PKA/CREB Pathway

Chronic stress disrupts dopamine (DA) transmission, adversely affecting mood and contribution to neuropsychiatric disorders like ADHD, autism, schizophrenia, anxiety, depression, and drug addiction. The neuropeptide oxytocin (OXT) plays a key role in social cognition, bonding, attachment, and parenting behaviors. In addition, OXT can modulate the activity of the HPA axis, counteracting the effects of stress, and alleviating fear and anxiety. However, whether OXT can mitigate stress-induced DA dysfunction and the underlying mechanisms remains unclear. This study investigated the neuroprotective effects of OXT on corticosterone (CORT) induced DA dysfunction in the neuroblastoma cell line SH-SY5Y. The results revealed that CORT decreases the levels of intracellular signaling molecules associated with DA function, including phosphorylated tyrosine hydroxylase (pTH), phosphorylated cAMP response element-binding protein (pCREB), and protein kinase A (PKA). Interestingly, pretreatment with OXT mitigated CORT-induced DA dysfunction through its potent PKA activator properties. In addition, the neuroprotective effect of OXT was abolished by atosiban (an OXT receptor antagonist) or H89 (a PKA inhibitor). Our results suggest that OXT protects dopaminergic neuroblastoma cells from CORT-induced DA dysfunction, potentially through the involvement of oxytocin receptors and the PKA/CREB signaling pathway. These findings contribute to the understanding of the neurobiological mechanisms underlying stress resilience and highlight potential pathways for developing targeted treatments that leverage the neuroprotective properties of OXT to address disorders characterized by DA dysregulation and impaired stress responses.

The Role of Oxytocin and Vasopressin in People with Borderline Personality Disorder: A Closer Look at Adolescents

Borderline personality disorder constitutes a significant medical challenge. Despite the fact that its occurrence among adolescents is currently attracting increasing interest from both clinicians and researchers, there is still insufficient data on this phenomenon. The etiology and maintenance of borderline personality disorder are not yet fully comprehended. Neuropeptides, including oxytocin and vasopressin, are considered to be involved in the development of this condition. The mechanism behind the actions of these neurohormones requires further investigation. Our work aims to collect and analyze the available research and existing hypotheses on the role of oxytocin and vasopressin in people with borderline personality disorder, with special attention drawn to adolescents suffering from this condition.

Effect of a Group-Based Personal Assistive RObot (PARO) Robot Intervention on Cognitive Function, Autonomic Nervous System Function, and Mental Well-being in Older Adults with Mild Dementia: A Randomized Controlled Trial

OBJECTIVES

Personal Assistive RObot (PARO) interventions have been used to treat agitation and mood symptoms of dementia effectively. However, the effects of a PARO intervention on physiological and cognitive function are unclear. To examine the effects of a group-based PARO intervention for older adults with mild dementia.

DESIGN

Using a group-based PARO intervention randomized controlled trial with 2-arm parallel groups.

SETTING AND PARTICIPANTS

Older adults with mild dementia aged 65 years or older from 4 dementia day care centers were recruited.

METHODS

Physiological parameters were assessed using the finger tapping test (FTT) and heart rate variability (HRV). The Mini-Mental State Examination (MMSE), Geriatric Depression Scale-Short Form (GDS-SF), University of California Los Angeles loneliness scale-version 3 (UCLA-3), and Warwick-Edinburgh Mental Well-being Scale (WEMWBS) were assessed before the intervention, end of the intervention, and 1-month after the intervention.

RESULTS

Using a repeated-measures generalized linear model, significant time × group interactions were found in the MMSE [F(2, 115) = 19.54, P < .001], FTT [F(2, 115) = 4.87, P = .01], HRV high-frequency [F(2, 115) = 3.57, P = .03], and high-frequency/low-frequency ratio [F(2, 115) = 0.96, P = .01], UCLA-3 [F(2, 115) = 54.7, P < .001], GDS-SF [F(2, 115) = 3.36, P = .04], and WEMWBS [F(2, 115) = 5.93, P < .001]. Furthermore, psychological parameters improved significantly and continuously even 1 month after the PARO intervention was finished. Physiological parameters significantly improved at week 6, but the effects had diminished by week 10.

CONCLUSIONS AND IMPLICATIONS

A PARO intervention may effectively improve the physiological and psychological responses of people with mild dementia.

The Effect of Environmental Enrichment on Selected Physiological and Immunological Stress-Related Markers in Dairy Goats

Homeostasis preservation is essential for animal survival, and any event that causes a disturbance in homeostasis is defined as a stressor. Here, we aimed to evaluate the effect of scratch brushes and stages as an environmental enrichment to alleviate stress in dairy goats. Twenty-four mixed-breed goats were divided into two groups according to common physiological conditions in breeding farms: milking and dry (milk-producing and non-milk-producing, respectively). Ten days after exposure to environmental enrichment treatment or not (control), blood was sampled. Following the enrichment, we observed a reduction in reactive oxidative stress metabolites, advanced glycation end products (AGEs), and their binding protein (transferrin) in the dry goats, as determined by an ELISA. In contrast, no change in AGEs, along with an increase in transferrin levels, was observed in the milking goats. Moreover, oxytocin levels decreased in the dry and increased in the milking goats, while serotonin levels increased in the dry and remained unchanged in the milking goats. Additionally, gene expression of the cytokines, IL-6 and IL-1ß, and anti-oxidative proteins, lysozyme and transferrin (in peripheral blood leukocytes), as determined by qPCR, presented the same pattern: down-regulation in the dry or up-regulation in the milking goats. In conclusion, a reliable methodology was developed for measuring husbandry stress in goats and to improve dairy goats' husbandry practice. Current environmental enrichment produced different responsiveness in goats correlated to their physiological status: beneficial effect in dry goats, detrimental effect in milking goats.

Egalitarian cooperation linked to central oxytocin levels in communal breeding house mice

Relationships between adult females are fundamental to understanding diversity in animal social systems. While cooperative relationships between kin are known to promote fitness benefits, the proximate mechanisms underlying this are not well understood. Here we show that when related female house mice (Mus musculus domesticus) cooperate to rear young communally, those with higher endogenous oxytocin levels have more egalitarian and successful cooperative relationships. Sisters with higher oxytocin concentrations in the paraventricular nucleus (PVN) of the hypothalamus weaned significantly more offspring, had lower reproductive skew and spent more equal proportions of time in the nest. By contrast, PVN oxytocin was unrelated to the number of weaned offspring produced in the absence of cooperation, and did not vary in response to manipulation of nest site availability or social cues of outgroup competition. By linking fitness consequences of cooperation with oxytocin, our findings have broad implications for understanding the evolution of egalitarian social relationships.

The central oxytocinergic system of the prairie vole

Oxytocin (OXT) is a peptide hormone and a neuropeptide that regulates various peripheral physiological processes and modulates behavioral responses in the central nervous system. While the humoral release occurs from the axons arriving at the median eminence, the neuropeptide is also released from oxytocinergic cell axons in various brain structures that contain its receptor, and from their dendrites in hypothalamic nuclei and potentially into the cerebrospinal fluid (CSF). Understanding oxytocin's complex functions requires the knowledge on patterns of oxytocinergic projections in relationship to its receptor (OXTR). This study provides the first comprehensive examination of the oxytocinergic system in the prairie vole (Microtus ochrogaster), an animal exhibiting social behaviors that mirror human social behaviors linked to oxytocinergic functioning. Using light and electron microscopy, we characterized the neuroanatomy of the oxytocinergic system in this species. OXT+ cell bodies were found primarily in the hypothalamus, and axons were densest in subcortical regions. Examination of the OXT+ fibers and their relationship to oxytocin receptor transcripts (Oxtr) revealed that except for some subcortical structures, the presence of axons was not correlated with the amount of Oxtr across the brain. Of particular interest, the cerebral cortex that had high expression of Oxtr transcripts contained little to no fibers. Electron microscopy is used to quantify dense cored vesicles (DCV) in OXT+ axons and to identify potential axonal release sites. The ependymal cells that line the ventricles were frequently permissive of DCV-containing OXT+ dendrites reaching the third ventricle. Our results highlight a mechanism in which oxytocin is released directly into the ventricles and circulates throughout the ventricular system, may serve as the primary source for oxytocin that binds to OXTR in the cerebral cortex.

Association between maltreatment, hair cortisol concentration, positive parent-child interaction, and psychosocial outcomes in Chinese preschool children

Children now are facing an increasing risk of early life stress (ELS), which leads to detrimental psychosocial outcomes. Behavior studies suggested that positive parental interactions might moderate the negative impact of ELS, but the related biological alteration remains unclear. This study aims to investigate whether positive parent-child interactions moderate the association between maltreatment (as a severe form of ELS) and hair cortisol concentration (HCC), as well as between HCC and psychosocial outcomes in young children. Participants were 6-year-old Chinese children (N = 257, Mage = 6.2, 121 were male) selected by stratified cluster random sampling from a Shanghai population representative cohort. Proximal 3 cm hair strands were analyzed using liquid chromatography coupled with tandem mass spectrometry for HCC. Children's psychosocial outcome was evaluated using the parental report Strengths and Difficulties Questionnaire (SDQ). Parents also reported the frequency of positive parent-child interactions using the Chinese Parent-Child Interaction Scale (CPCIS) as well as the history of maltreatment. Multi-level logistic regression models adjusting for individual, kindergarten, and district confounders were used to evaluate the associations between maltreatment, HCC, and psychosocial outcomes. Interactions terms tested whether more frequent positive parent-child interactions moderates the association between maltreatment and HCC, as well as between HCC and psychosocial outcomes. Maltreated children exhibited higher levels of HCC (B = 1.20, 95% CI: 0.38,2.02; p = 0.004), and children with higher HCC exhibited poorer psychosocial outcomes (B = 0.34, 95% CI: 0.18,0.51; p < 0.001). Positive parent-child interactions did not have a moderating effect on the association between maltreatment and HCC, but they demonstrated a moderating effect on the association between increased HCC and psychosocial outcomes (interaction term: B = -0.42, 95% CI: -0.75,-0.10; p = 0.01). These findings provide evidence that positive parental interaction may serve as a moderator between chronic cortisol exposure and psychosocial problems. It highlights the importance of frequent parent-child interactions, especially among children under a high risk of ELS.

Severe PTSD is marked by reduced oxytocin and elevated vasopressin

Neuroendocrine analyses of posttraumatic stress disorder (PTSD) have generally focused on hypothalamic-pituitary-adrenal (HPA) axis alterations. In the present analyses, we examine two additional neuroendocrine factors that have been previously implicated in biological stress responses: oxytocin (OT) and arginine vasopressin (AVP). Here we examined basal neuropeptide status in military veterans clinically diagnosed with PTSD (n = 29) and in two non-traumatized comparison groups with previous stress exposure (n = 11 SWAT trainees and n = 21 ultramarathon runners). PTSD patients showed low levels of plasma OT and high levels of AVP. The ratio of AVP/OT robustly related to PTSD status, and emerged as a statistically plausible mediator of relationships between the number of personal traumatic experiences and subsequent PTSD symptom burden. Over the course of behavioral therapy for PTSD, measures of OT showed a significant but modest normalization. Plasma cortisol levels were not statistically different among the three groups. This study suggests that AVP/OT ratios may represent a neuroendocrine predictor of severe PTSD, as well as a potential treatment response biomarker.

Trauma-informed care

In recent years, trauma informed care has become a heavily researched topic; however, it has yet to achieve a universal standard in the field of pediatric medicine. One of the primary tenants of trauma informed care is a clear understanding of the pervasiveness and complexities of childhood trauma, and its intersection with a child and caregiver's physical wellness. A major component of trauma informed care is addressing the way medical providers may be exposed to vicarious trauma, secondary traumatic stress, and compassion fatigue. By taking proactive steps to educate medical providers on the effects of trauma, they are better equipped to assess a family's needs and provide enhanced quality of care for their patients and themselves.

An overview of the differences in the pharmacological management of post-traumatic stress disorder between women and men

INTRODUCTION

Post-traumatic stress disorder (PTSD) is a disabling psychiatric condition with a worldwide prevalence between 6% and 9%, and more common in the female than in the male sex. The aim of this paper is to review and comment on the different factors that might explain the discrepancies in the pharmacological management of women and men.

AREAS COVERED

The available literature shows that there exists a vulnerability of women to develop PTSD that may depend on neurobiological as well as environmental/cultural factors. These variables might influence the clinical picture, the outcome and the response to specific treatments, given their consequences on the pharmacokinetics of commonly prescribed drugs. Women suffering from PTSD are more prone to consult and receive more prescriptions of psychotropic drugs than men. However, it is evident that the particular stages of a women's life such as pregnancy or breastfeeding might require a specific evaluation and care.

EXPERT OPINION

It is necessary to explore the pharmacokinetics of compounds highlighting sex-related differences, and their safety during pregnancy and lactation. Taking care of differences between women and men should represent a main focus of research, while being a primary target towards a really tailored pharmacological treatment of PTSD.

Oxytocin predicts positive affect gains in a role-play interaction

Introduction

Role-play, a key creative process in theatre, is used in therapeutic interventions to improve social skills, emotion regulation, and memory. Although role-play is widely used as a psychotherapeutic technique, its mechanisms of action are not fully understood.

Methods

Our study introduces a standardized controlled procedure for promoting role-play in the laboratory based on the portrayal of a fictional persona and examines its effects on anxiety, affect, prosocial attitudes, and salivary oxytocin dynamics in 38 participants.

Results

In our experiment, role-play significantly increased positive affect and prosocial attitudes and decreased anxiety compared to a control condition. Basal salivary oxytocin levels predicted higher gains in positive affect following role-play, suggesting a specific moderating effect of oxytocin. The fictional persona used in the procedure was rated as very happy by subjects, creating a positive social context for the role-play social interaction.

Discussions

We propose that the observed moderation effect of oxytocin in our study is specific to the role-play condition due to the capacity of role-play to generate an affective regulatory context based on congruency toward the emotional state of the fictional persona. Our findings indicate that basal oxytocin levels could predict specific outcomes of role-play in therapeutical setting. We discuss several psychological and biological mechanisms that could account for the observed effects of role-play and how oxytocin could act as a substrate for them.

The Influence of Social Dynamics on Biological Aging and the Health of Historically Marginalized Populations: A Biopsychosocial Model for Health Disparities

Historically marginalized populations are susceptible to social isolation resulting from their unique social dynamics; thus, they incur a higher risk of developing chronic diseases across the course of life. Research has suggested that the cumulative effect of aging trajectories per se, across the lifespan, determines later-in-life disease risks. Emerging evidence has shown the biopsychosocial effects of social stress and social support on one's wellbeing in terms of inflammation. Built upon previous multidisciplinary findings, here, we provide an overarching model that explains how the social dynamics of marginalized populations shape their rate of biological aging through the inflammatory process. Under the framework of social stress and social support theories, this model aims to facilitate our understanding of the biopsychosocial impacts of social dynamics on the wellbeing of historically marginalized individuals, with a special emphasis on biological aging. We leverage this model to advance our mechanistic understanding of the health disparity observed in historically marginalized populations and inform future remediation strategies.

Neural mechanisms of different types of envy: a meta-analysis of activation likelihood estimation methods for brain imaging

Previous studies have a lack of meta-analytic studies comparing the trait (personality) envy, social comparison envy, and love-envy, and the understanding of the similarities and differences in the neural mechanisms behind them is relatively unclear. A meta-analysis of activation likelihood estimates was conducted using 13 functional magnetic resonance imaging studies. Studies first used single meta-analyses to identify brain activation areas for the three envy types. Further, joint and comparative analyses were followed to assess the common and unique neural activities among the three envy types. A single meta-analysis showed that the critical brain regions activated by trait (personality) envy included the inferior frontal gyrus, cingulate gyrus, middle frontal gyrus, lentiform nucleus and so on. The critical brain regions activated by social comparison envy included the middle frontal gyrus, inferior frontal gyrus, medial frontal gyrus, precuneus and so on. The critical brain regions activated by love-envy included the inferior frontal gyrus, superior frontal gyrus, cingulate gyrus, insula and so on. In terms of the mechanisms that generate the three types of envy, each of them is unique when it comes to the perception of stimuli in a context; in terms of the emotion regulation mechanisms of envy, the three types of envy share very similar neural mechanisms. Both their generation and regulation mechanisms are largely consistent with the cognitive control model of emotion regulation. The results of the joint analysis showed that the brain areas co-activated by trait (personality) envy and social comparison envy were frontal sub-Gyral, inferior parietal lobule, inferior frontal gyrus, precuneus and so on; the brain areas co-activated by trait (personality) envy and love-envy were extra-nuclear lobule, lentiform nucleus, paracentral lobule, cingulate gyrus and so on; the brain regions that are co-activated by social comparison envy and love-envy are anterior cingulate gyrus, insula, supramarginal gyrus, inferior frontal gyrus and so on. The results of the comparative analysis showed no activation clusters in the comparisons of the three types of envy.

The Relation between Plasma Nesfatin-1 Levels and Aggressive Behavior in Pit Bull Dogs

Aggression is a prevalent and concerning behavioral issue in dogs. Pit Bull dogs, known for their high levels of aggression, are recognized as a focus of concern in society. In our study, we aimed to investigate the behavioral characteristics of Pit Bull dogs and explore the potential roles of peptides involved in the neurobiology of aggression. Initially, female, and male dogs underwent aggression tests, and their aggression levels were categorized. Plasma nesfatin-1, serotonin, oxytocin, and dopamine levels were quantified using ELISA, with blood samples collected after a 24 h fasting period and 2 h post-refeeding. Our findings indicate that aggression in Pit Bull dogs correlates with decreased plasma nesfatin-1, serotonin, and oxytocin levels, while dopamine levels increase. The study's findings indicate that fasted dogs exhibited lower plasma levels of nesfatin-1, serotonin, and dopamine, while plasma oxytocin levels were higher. Furthermore, while the research findings do not suggest a significant relationship between the severity of aggression and the gender of the dog, male Pit Bull breeds appear to have higher plasma nesfatin-1 and serotonin levels compared to their female counterparts. The study's findings demonstrate that nesfatin-1, serotonin, oxytocin, and dopamine play pivotal roles in Pit Bull dogs' aggression, indicating potential interactions among these neuropeptides at the central nervous system level.

Calm Contact Technique Based on the Endocrinological Mechanism of Hypnosis-A Theoretical Proposal

This paper proposes the "calm contact" technique: an imaginative scenario where someone is in gentle contact with a loved one where the essence of the experience is to enjoy safety and calmness in peaceful social contact. The theoretical background is outlined by combining the brain mechanisms of stress reactions and hypnosis. In addition to the ancient stress responses (flight or fight or freeze), there are oxytocin-based options at the human level: tend and befriend behavior and the state of calm and connection, which is not a stress reaction but a resting reaction. These social-based reactions could prevent the organism from the primitive freezing response. Some studies proved that "hypnosis" as a setting reduces cortisol levels and could raise oxytocin levels. The beneficial mechanisms of the "calm contact" technique are analyzed in relation to "social support" and the psychoaffective effects of central oxytocin. The subjective effects of the proposed technique are outlined based on reports of healthy volunteers. The "calm contact" technique could be an alternative or adjunct to the "safe place" technique, applying the recent findings of endocrinological brain mechanisms of hypnosis. Clinical implications and limitations are briefly summarized.

Oxytocin as a transdiagnostic biomarker of well-being in severe mental illness during the Covid-19 pandemic

Individuals with severe mental illness (SMI) have been found to suffer a greater decline in psychological well-being compared to the general population in times of stress. The present study aimed to examine clinical and endocrine resilience factors of psychological well-being in SMI patients during the Covid-19 pandemic.

METHODS

After Covid-19 crisis outburst in Israel 112 participants, 69 outpatients, and 43 inpatients and day treatment patients were recruited. Outpatients signed an online informed consent and filled in questionnaires regarding their level of mental health symptoms (OQ-45), fear of Covid-19 (FCV), and psychological well-being (PWB). Inpatients answered the same questionnaires and in addition, went through a positive social interaction paradigm while providing three saliva samples to measure their s-IgA and oxytocin (OT) levels.

RESULTS

A strong negative correlation was found in the whole sample between reported mental health symptoms, fear of Covid-19, and well-being. Hierarchical regression did not find additional contribution of the fear of the pandemic in predicting well-being beyond the impact of symptomatology. For inpatients (N = 39) only, hierarchical regression found that oxytocin, but not s-IgA could explain 5% of the variance of well-being (R2 = 0.05) in individuals with SMI regardless of their mental health symptoms (R2 = 0.46) and their marital status (R2 = 0.21).

CONCLUSIONS

OT is suggested as a possible independent biological resilience factor of well-being in times of major stress among SMI patients. It is still unknown whether OT is a mediator that contributes to well-being or a biological marker that indicates the degree of beneficial social interactions.

Efficacy of 1,5-anhydro-D-fructose on reducing mental stress: a randomized, double-blind, placebo-controlled trial-a pilot study

Brain-derived neurotrophic factor (BDNF) plays an important role in mental stress. We have previously reported that 1,5-anhydro-D-fructose (1,5-AF) increases brain BDNF in vivo. The present randomized, controlled, double-blind study aimed to clinically evaluate the effects of 1,5-AF oral intake on mental stress in terms of three parameters: sleep, mood, and bowel issues. Healthy volunteers aged between 22 and 71 years (n = 24) were randomly assigned to receive 5.5 g of 1,5-AF or placebo orally, once daily for 4 weeks. Pre- and post-intervention, the subjects completed the Oguri-Shirakawa-Azumi Sleep Inventory, Middle-Aged and Aged Version (OSA-MA); Profile of Mood States, Second Edition (POMS2); and Constipation Assessment Scale (CAS) questionnaires. In the OSA-MA, both "sleepiness on rising" and "sleep length" were significantly improved after treatment with 1,5-AF compared with before treatment. Furthermore, in the POMS2, there was a clear tendency toward reduced "Anger-Hostility" in the 1,5-AF group after treatment, and in the CAS, there was a clear tendency toward reduced "diarrhea or liquid stool" in the 1,5-AF group after treatment. Together, our findings indicate that 1,5-AF has some effects on reducing post-intervention mental stress levels.

Oxytocin enhances the triangular association among behavior, resting-state, and task-state functional connectivity

Considerable advances in the role of oxytocin (OT) effect on behavior and the brain network have been made, but the effect of OT on the association between inter-individual differences in functional connectivity (FC) and behavior is elusive. Here, by using a face-perception task and multiple connectome-based predictive models, we aimed to (1) determine whether OT could enhance the association among behavioral performance, resting-state FC (rsFC), and task-state FC (tsFC) and (2) if so, explore the role of OT in enhancing this triangular association. We found that in the OT group, the prediction performance of using rsFC or tsFC to predict task behavior was higher than that of the PL group. Additionally, the correlation coefficient between rsFC and tsFC was substantially higher in the OT group than in the PL group. The strength of these associations could be partly explained by OT altering the brain's FCs related to social cognition and face perception in both the resting and task states, mainly in brain regions such as the limbic system, prefrontal cortex, temporal poles, and temporoparietal junction. Taken together, these results provide novel evidence and a corresponding mechanism for how neuropeptides cause increased associations among inter-individual differences across different levels (e.g., behavior and large-scale brain networks in both resting and task-state), and may inspire future research on the role of neuropeptides in the cross levels association of both clinical and nonclinical use.

Functional brain changes after alternative pharmacological interventions in posttraumatic stress disorder: A systematic review of clinical trials

BACKGROUND

Posttraumatic stress disorder (PTSD) is a complex and heterogeneous mental health condition that can develop after exposure to a traumatic event. Clinical trials have used alternative pharmacological agents to treat PTSD, but their associated neural correlates remain unclear. The present systematic review aims to summarize the changes in brain function associated with the use of these alternative pharmacological agents in PTSD.

METHODS

Clinical trials using functional magnetic resonance imaging, either at rest or during the performance of tasks, were included if they compared the effects of alternative pharmacological agents between PTSD patients and either trauma-exposed controls or never-exposed healthy controls.

RESULTS

Sixteen studies were included, of which 11 used intranasal oxytocin, 2 used hydrocortisone, and 3 used delta-9-tetrahydrocannabinol (THC). Oxytocin administration was associated with the normalization of functional connectivity between the ventromedial prefrontal cortex and amygdala as well as enhanced the function of brain regions specifically involved in emotion processing (e.g., amygdala), working memory (e.g., dorsolateral prefrontal cortex), and reward (e.g., putamen). Hydrocortisone did not influence brain function at rest or during the performance of an autobiographical memory task, whereas THC was associated with the reduction of the amygdala and increased medial prefrontal cortex activation.

CONCLUSIONS

This systematic review identified preliminary evidence for normalizing brain function after the use of alternative pharmacological agents. Importantly, sex-specific differences were noted, in particular when using oxytocin, that will require further investigation.

Negative Stressful Life Events and Social Support Are Associated With White Matter Integrity in Depressed Patients and Healthy Control Participants: A Diffusion Tensor Imaging Study

BACKGROUND

Negative stressful life events and deprivation of social support play critical roles in the development and maintenance of major depressive disorder (MDD). The present study aimed to investigate in a large sample of patients with MDD and healthy control participants (HCs) whether these effects are also reflected in white matter (WM) integrity.

METHODS

In this diffusion tensor imaging study, 793 patients with MDD and 793 age- and sex-matched HCs were drawn from the Marburg-Münster Affective Disorders Cohort Study (MACS) and completed the Life Events Questionnaire (LEQ) and Social Support Questionnaire (SSQ). Generalized linear models were performed to test voxelwise associations between fractional anisotropy (FA) and diagnosis (analysis 1), LEQ (analysis 2), and SSQ (analysis 3). We examined whether SSQ interacts with LEQ on FA or is independently associated with improved WM integrity (analysis 4).

RESULTS

Patients with MDD showed lower FA in several frontotemporal association fibers compared with HCs (pTFCE-FWE = .028). Across both groups, LEQ correlated negatively with FA in widely distributed WM tracts (pTFCE-FWE = .023), while SSQ correlated positively with FA in the corpus callosum (pTFCE-FWE = .043). Modeling the combined association of both variables on FA revealed significant-and antagonistic-main effects of LEQ (pTFCE-FWE = .031) and SSQ (pTFCE-FWE = .037), but no interaction of SSQ × LEQ.

CONCLUSIONS

Our results indicate that negative stressful life events and social support are both related to WM integrity in opposing directions. The associations did not differ between patients with MDD and HCs, suggesting more general, rather than depression-specific, mechanisms. Furthermore, social support appears to contribute to improved WM integrity independent of stressful life events.

Microbes, oxytocin and stress: Converging players regulating eating behavior

Oxytocin is a peptide-hormone extensively studied for its multifaceted biological functions and has recently gained attention for its role in eating behavior, through its action as an anorexigenic neuropeptide. Moreover, the gut microbiota is involved in oxytocinergic signaling through the brain-gut axis, specifically in the regulation of social behavior. The gut microbiota is also implicated in appetite regulation and is postulated to play a role in central regulation of hedonic eating. In this review, we provide an overview on oxytocin and its individual links with the microbiome, the homeostatic and non-homeostatic regulation of eating behavior as well as social behavior and stress.

Pain perception and physiological responses are modulated by active support from a romantic partner

As social animals, humans are strongly affected by social bonds and interpersonal interactions. Proximity and social support from significant others may buffer the negative outcomes of a painful experience. Several studies have investigated the role of romantic partners' support in pain modulation, mostly focusing on tactile support and showing its effectiveness in reducing pain perception. Nevertheless, no study so far has investigated the role of supportive speaking on pain modulation, nor has compared the effects of a tactile and vocal support within the same couples. The present study directly compared for the first time the efficacy of mere presence (Passive Support) and different forms of active (Touch, Voice, Touch + Voice) support from a romantic partner during a painful experience in a naturalistic setting. We assessed pain modulation in 37 romantic couples via both subjective (self-reported ratings) and physiological (skin conductance) measurements. We found that all three types of active support were equally more effective than passive support in reducing the painful experience at both subjective and physiological levels; interestingly, our results suggest that supportive speaking can reduce pain perception with respect to passive support to a similar extent as tactile support does. Overall, this study highlights the relevance of an active support in reducing pain perception, with active types of support being more effective than passive support, regardless of its specific modality.

Oxytocin Levels in Children with Separation Anxiety and Their Mothers before and after Treatment

Objective

The purpose of this study was to compare the plasma oxytocin levels of children with separation anxiety disorder (SAD) and their mothers with those of healthy controls and to examine the relationship between oxytocin levels and changes in anxiety three months after treatment.

Methods

Thirty children aged 6-12 years with SAD, 30 healthy children, and mothers of both groups were included in the study. All cases were evaluated with semi-structured interview and Clinical Global Impression Scale. All cases and mothers of both groups filled out scales to determine various psychological variables (anxiety, depression, and attachment). The patient group children were re-evaluated with their mothers after three months, following treatment. Plasma oxytocin levels were evaluated from both groups and their mothers before and after treatment.

Results

The plasma oxytocin levels of mothers of children with SAD were significantly lower than those of the controls and increased significantly three months after their children were treated. No difference was found between the plasma oxytocin levels of children with SAD and the control group, and these children's levels decreased significantly after treatment. A positive correlation was found between changes in the plasma oxytocin levels of children with SAD and the change in anxiety scores.

Conclusion

Our results show that the change in plasma oxytocin levels in both children and mothers after treatment suggests that oxytocin may be important in the etiology of SAD.

Salivary Oxytocin and Antioxidative Response to Robotic Touch in Adults with Autism Spectrum Disorder

Individuals with ASD are known to have a tendency to have tactile sensory processing issues that could be associated with their impairment as regards social communication. The alterations in tactile processing in autistic subjects are usually accompanied by hypersensitivity and other unpleasant emotions induced by tactile contact. In our study, we investigated the impact of the velocity and the force of a tactile stroke received impersonally by a custom-built robotic device. A total of 21 adults with ASD and 22 adults from a control group participated in our study. The participants' responses were assessed according to subjective scales, EEG changes, and the dynamics of saliva antioxidants and oxytocin. It was found that the oxytocin level was significantly lower in subjects with ASD but increased after tactile stimulation. However, contrary to expectations, the increase in the oxytocin level in the target group negatively correlated with the subjective pleasantness of tactile stimulation and was probably associated with a stress-induced effect. The basic levels of antioxidants did not differ between the TD and ASD groups; however, these had significantly increased in individuals with ASD by the end of the study. The EEG findings, which revealed enhanced antioxidant levels, contributed to the relief of the cognitive control during the study.

Exogenous oxytocin administration during labor and autism spectrum disorder

BACKGROUND

Oxytocin is a neuropeptide hormone that plays a key role in social behavior, stress regulation, and mental health. Synthetic oxytocin administration is a common obstetrical practice, and importantly, previous research has suggested that intrapartum exposure may increase the risk of neurodevelopmental disorders, such as autism spectrum disorder.

OBJECTIVE

This study aimed to examine the association between synthetic oxytocin exposure during labor and autism spectrum disorder diagnosis in the child.

STUDY DESIGN

This population-based retrospective cohort study compared 2 cohorts of children: (1) all children born in British Columbia, Canada between April 1, 2000 and December 31, 2014 (n=414,336 births), and (2) all children delivered at Soroka University Medical Center in Be'er-Sheva, Israel between January 1, 2011 and December 31, 2019 (n=82,892 births). Nine different exposure groups were examined. Cox proportional hazards models were used to estimate crude and adjusted hazard ratios of autism spectrum disorder in both cohorts on the basis of induction and/or augmentation exposure status. To further control for confounding by indication, we conducted sensitivity analyses among a cohort of healthy, uncomplicated deliveries and among a group that was induced only for postdates. In addition, we stratified our analyses by infant sex to assess for potential sex differences.

RESULTS

In the British Columbia cohort, 170,013 of 414,336 deliveries (41.0%) were not induced or augmented, 107,543 (26.0%) were exposed to oxytocin, and 136,780 (33.0%) were induced or augmented but not exposed to oxytocin. In the Israel cohort, 51,790 of 82,892 deliveries (62.5%) were not induced or augmented, 28,852 (34.8%) were exposed to oxytocin, and 2250 (2.7%) were induced or augmented but not exposed to oxytocin. On adjusting for covariates in the main analysis, significant associations were observed in the Israel cohort, including adjusted hazard ratios of 1.51 (95% confidence interval, 1.20-1.90) for oxytocin-augmented births and 2.18 (95% confidence interval, 1.32-3.57) for those induced by means other than oxytocin and not augmented. However, oxytocin induction was not significantly associated with autism spectrum disorder in the Israel cohort. In the Canadian cohort, there were no statistically significant adjusted hazard ratios. Further, no significant sex differences were observed in the fully adjusted models.

CONCLUSION

This study supports that induction of labor through oxytocin administration does not increase the risk of autism spectrum disorder in the child. Our international comparison of 2 countries with differences in clinical practice regarding oxytocin administration for induction and/or augmentation suggests that previous studies reporting a significant association were likely confounded by the underlying indication for the induction.

Hypothalamus and Post-Traumatic Stress Disorder: A Review

Humans have lived in a dynamic environment fraught with potential dangers for thousands of years. While fear and stress were crucial for the survival of our ancestors, today, they are mostly considered harmful factors, threatening both our physical and mental health. Trauma is a highly stressful, often life-threatening event or a series of events, such as sexual assault, war, natural disasters, burns, and car accidents. Trauma can cause pathological metaplasticity, leading to long-lasting behavioral changes and impairing an individual's ability to cope with future challenges. If an individual is vulnerable, a tremendously traumatic event may result in post-traumatic stress disorder (PTSD). The hypothalamus is critical in initiating hormonal responses to stressful stimuli via the hypothalamic-pituitary-adrenal (HPA) axis. Linked to the prefrontal cortex and limbic structures, especially the amygdala and hippocampus, the hypothalamus acts as a central hub, integrating physiological aspects of the stress response. Consequently, the hypothalamic functions have been attributed to the pathophysiology of PTSD. However, apart from the well-known role of the HPA axis, the hypothalamus may also play different roles in the development of PTSD through other pathways, including the hypothalamic-pituitary-thyroid (HPT) and hypothalamic-pituitary-gonadal (HPG) axes, as well as by secreting growth hormone, prolactin, dopamine, and oxytocin. This review aims to summarize the current evidence regarding the neuroendocrine functions of the hypothalamus, which are correlated with the development of PTSD. A better understanding of the role of the hypothalamus in PTSD could help develop better treatments for this debilitating condition.

The Role of Oxytocin in Early-Life-Stress-Related Neuropsychiatric Disorders

Early-life stress during critical periods of brain development can have long-term effects on physical and mental health. Oxytocin is a critical social regulator and anti-inflammatory hormone that modulates stress-related functions and social behaviors and alleviates diseases. Oxytocin-related neural systems show high plasticity in early postpartum and adolescent periods. Early-life stress can influence the oxytocin system long term by altering the expression and signaling of oxytocin receptors. Deficits in social behavior, emotional control, and stress responses may result, thus increasing the risk of anxiety, depression, and other stress-related neuropsychiatric diseases. Oxytocin is regarded as an important target for the treatment of stress-related neuropsychiatric disorders. Here, we describe the history of oxytocin and its role in neural circuits and related behaviors. We then review abnormalities in the oxytocin system in early-life stress and the functions of oxytocin in treating stress-related neuropsychiatric disorders.

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.

Oxytocin and eating disorders: Knowledge gaps and future directions

Eating disorders continue to be a major public health issue and important cause of morbidity and premature mortality, particularly for young people. Yet in a concerning dialectic, this occurs in the context of an epidemic of obesity which, with its medical complications, constitutes another vexing public health challenge. While it is not an eating disorder per se obesity is often comorbid with eating disorders. Effective treatment for both eating disorders and obesity has proven to be elusive and in the search for novel therapeutic interventions, the prosocial, anxiolytic, brain plasticity and metabolic effects of oxytocin (OT) have been examined from this perspective. The availability of intranasal oxytocin (IN-OT) has led to a number of interventional treatment studies in anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), their atypical and subclinical forms and in medical and psychiatric conditions co-occurring or comorbid with these, obesity with BED would be included here. The aim of this mini review is to collate recent findings on OT as a novel therapeutic intervention in eating disorders and obesity and to identify and address some of the knowledge gaps in the use of IN-OT. The wider clinical perspective utilised here might better address some of the gaps and identify future directions of research. Clearly much remains to be done for OT to fulfil its therapeutic promise in eating disorders. OT might yet be of therapeutic promise and will be appreciated where treatment advances have been hard to come by and prevention challenging for these disorders.

Toward consistent reporting of sample characteristics in studies investigating the biological mechanisms of romantic love

In this non-systematic review, we consider the sample reporting practices of 42 studies up to and including 2021 investigating the biological mechanisms of romantic love (i.e., 31 neuroimaging studies, nine endocrinological studies, one genetics study, and one combined neuroimaging and genetics study). We searched scientific databases using key terms and drew on our and other authors' knowledge to identify studies that investigated the mechanisms associated with romantic love using neuroimaging, endocrinological, and genetic methods. Only studies with a group or entire sample experiencing romantic love were included. The aim was to collate all relevant studies and determine the comparability of studies and ability to assess the generalizability of findings. We summarize how these studies report sex/gender, age, romantic love, relationship duration/time in love, and sample descriptors. We then outline the case for promoting comparability and the ability to determine generalizability in future studies. The findings indicate a limited ability to compare studies' samples or make an assessment of the generalizability of findings. Existing studies are not representative of the general population in a particular country or globally. We conclude by presenting ideas about how best to report sex, age, romantic love characteristics, relationship status, time in love, relationship duration, relationship satisfaction, type of unrequited love, sexual activity, cultural characteristics, socio-economic status, student status, and method-relevant descriptors. If our ideas are adopted, in part or in whole, we expect the comparability of studies to increase. Adopting our ideas will also make it easier to make an assessment of the generalizability of findings.

Quest for Biomarkers of Positive Health: A Review

The positive health of a person can be defined as the ability to live long in good health, possibly with no activity limitation. No method is yet available for its objective assessment in individuals, and we propose a framework in this communication that can operationalize this concept. Instead of distal factors, such as diet and lifestyle because these are subjective and difficult to measure, we concentrate on the objectively measurable biomarkers such as immunity level, endorphins, and handgrip strength. The focus is on the major parameters that may protect from diseases and infirmity and can be assessed by noninvasive methods. A combination of such parameters may signify positive health. This may be a novel way to measure positive health at the individual level. In this communication, we briefly review the literature and identify a few major biomarkers that provide a protective shield and could determine the status of positive health at the individual level. This exercise demonstrates that the assessment of the positive health of a person is feasible. A scale based on these and other relevant parameters can be developed later that could quantitatively measure the exact level of positive health. As the exact combination of the parameters that protects from ailments is not fully known yet, a framework such as this may help in identifying the data gaps that require attention in this context. The proposed framework may initiate a discussion on indicators of positive health and characterize the parameters for intervention that could increase a healthy life.

Prolactin and oxytocin: potential targets for migraine treatment

Migraine is a severe neurovascular disorder of which the pathophysiology is not yet fully understood. Besides the role of inflammatory mediators that interact with the trigeminovascular system, cyclic fluctuations in sex steroid hormones are involved in the sex dimorphism of migraine attacks. In addition, the pituitary-derived hormone prolactin and the hypothalamic neuropeptide oxytocin have been reported to play a modulating role in migraine and contribute to its sex-dependent differences. The current narrative review explores the relationship between these two hormones and the pathophysiology of migraine. We describe the physiological role of prolactin and oxytocin, its relationship to migraine and pain, and potential therapies targeting these hormones or their receptors.In summary, oxytocin and prolactin are involved in nociception in opposite ways. Both operate at peripheral and central levels, however, prolactin has a pronociceptive effect, while oxytocin appears to have an antinociceptive effect. Therefore, migraine treatment targeting prolactin should aim to block its effects using prolactin receptor antagonists or monoclonal antibodies specifically acting at migraine-pain related structures. This action should be local in order to avoid a decrease in prolactin levels throughout the body and associated adverse effects. In contrast, treatment targeting oxytocin should enhance its signalling and antinociceptive effects, for example using intranasal administration of oxytocin, or possibly other oxytocin receptor agonists. Interestingly, the prolactin receptor and oxytocin receptor are co-localized with estrogen receptors as well as calcitonin gene-related peptide and its receptor, providing a positive perspective on the possibilities for an adequate pharmacological treatment of these nociceptive pathways. Nevertheless, many questions remain to be answered. More particularly, there is insufficient data on the role of sex hormones in men and the correct dosing according to sex differences, hormonal changes and comorbidities. The above remains a major challenge for future development.

Oxytocin receptors mediate oxytocin potentiation of methylphenidate-induced stimulation of accumbens dopamine in rats

While the illicit use and misuse of stimulants like cocaine and methylphenidate (MP) has increased, there remains no FDA-approved treatments for psychostimulant use disorders (PSUD). Oxytocin (OT) has shown promise as a potential pharmacotherapy for PSUD. Dopamine (DA) neurotransmission plays a significant role in PSUD. We have recently shown that OT blunts the reinforcing effects of MP but, surprisingly, enhanced MP-induced stimulation of DA levels. Such effects have been suggested as a result of activation of OT receptors or, alternatively, could be mediated by direct actions of OT on MP blockade of the DA transporter. Here, we employed fast scan cyclic voltammetry (FSCV) to investigate the effects of systemic OT on MP-induced changes in the dynamics of DA, phasic release and uptake, in the nucleus accumbens shell (NAS) of Sprague-Dawley rats. We also tested the systemic effects of an antagonist of OT receptors, atosiban, to counteract the OT enhancement of dopaminergic effects of MP under microdialysis procedures in the NAS in rats. Administration of OT alone (2 mg/kg; i.p.) did not significantly modify evoked NAS DA dynamics measured by FSCV, and when administered 10 min before MP (0.1, 0.3, 1.0 mg/kg; i.v.), OT did not potentiate MP-induced increases in phasic DA release and did not alter DA clearance rate, suggesting no direct interactions of OT with the MP-induced blockade of DA uptake. Also, OT alone did not elicit significant changes in tonic, extracellular NAS DA levels measured by microdialysis. However, consistent with previous studies, we observed that OT pretreatments (2 mg/kg; i.p.) potentiated MP-induced (0.1, 0.3, 1.0 mg/kg; i.v.) efflux of extracellular NAS DA levels. This effect was abolished when rats were pretreated with atosiban (2 mg/kg; i.p.), suggesting that OT receptors mediate this OT action. Overall, our results suggest that OT receptors mediated OT potentiation of MP-induced stimulation of extracellular NAS DA levels, likely driven by modulation of DA receptor signaling pathways, without affecting MP blockade of DAT.

Pilot study of Qigong/Tai Chi Easy acute effects of meditative movement, breath focus and "flow" on blood pressure, mood and oxytocin in older adults

BACKGROUND

Older adults are increasingly lonely and at risk for hypertension. Endogenous oxytocin levels are associated with lowering blood pressure (BP), suggesting value in increasing oxytocin. Regular practice of Tai Chi improves BP and mood; we explored a single session of Tai Chi Easy (TCE) with older adults and feasibility of measuring oxytocin as a key biomarker.

METHOD

In a single-arm pre-post design pilot study, 21 older adults (age 55-80) with mild-moderate hypertension practiced a single session (50-min) TCE. BP, psychosocial measures, and saliva samples were collected pre/post to examine feasibility of acute measures of oxytocin and explore effect sizes of outcomes. Participants (N = 21; 19 % Latinx, 76.2 % female, mean age 66.76).

RESULTS

BP systolic: 138.43-134.86; diastolic 78.48-78.00 (p > .05; Cohen's d -0.23; -0.08 respectively). Total Mood Disturbance (TMD) and Connection (CN) improved [TMD mean pre 41.891 (SD=19.60) to post 35.00 (SD=10.21), p = .01; Cohen's d - 0.67); CN mean 7.85 (SD=2.01) to post 9.05 (SD=1.00), p = .01; Cohen's d 0.70]. Baseline oxytocin was positively correlated with baseline loneliness (N = 14, r = .599); pre/post oxytocin changes were negatively correlated with baseline loneliness (N = 14, r = -.585). BP decrease was associated with characteristics of the intervention: "flow" (coef=.=0.58N = 17) and meditative/breath focus (coef=-1.78; N = 17).

DISCUSSION/CONCLUSION

Medium to large effect sizes indicating change in mood and connection were found for this single session intervention. Knowing that Tai Chi improves BP when practiced over time, this TCE intervention shows promise for planning a fully powered, randomized controlled study of BP, mood and perceptions of connection in hypertensive older adults. Feasibility of assessing acute salivary oxytocin is less promising. Increase in oxytocin levels occurred for those less lonely, but declined for lonelier participants. With different responses based on baseline loneliness scores, no mean change in oxytocin levels was found. Seemingly unstable levels (possibly related to interaction with study staff) suggests the need for further testing in more controlled study designs. Finally, BP associations with meditative/breath focus and flow could be further explored in future study designs addressing mediation.

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.

Oxytocin vs. placebo effects on intrusive memory consolidation using a trauma film paradigm: a randomized, controlled experimental study in healthy women

Oxytocin administration during a trauma analogue has been shown to increase intrusive memories, which are a core symptom of post-traumatic stress disorder (PTSD). However, it is unknown whether oxytocin influences the acquisition or the consolidation of the trauma. The current study investigates the effect of the activation of the oxytocin system during the consolidation of an analogue trauma on the formation of intrusive memories over four consecutive days and whether this effect is influenced by individual neurobiological, genetic, or psychological factors. We conducted a randomized double-blind placebo-controlled study in 217 healthy women. They received either a single dose of intranasal oxytocin (24 IU) or placebo after exposure to a trauma film paradigm, which reliably induces intrusive memories. We used a general random forest to examine a potential heterogeneous treatment effect of oxytocin on the consolidation of intrusive memories. Furthermore, we used a poisson regression to examine whether salivary alpha amylase activity (sAA) as a marker of noradrenergic activity and cortisol response to the film, polygenic risk score (PRS) for psychiatric disorders, and psychological factors influence the number of intrusive memories. We found no significant effect of oxytocin on the formation of intrusive memories (F(2, 543.16) = 0.75, p = 0.51, ηp2 = 0.00) and identified no heterogeneous treatment effect. We replicated previous associations of the PRS for PTSD, sAA and the cortisol response on intrusive memories. We further found a positive association between high trait anxiety and intrusive memories, and a negative association between the emotion regulation strategy reappraisal and intrusive memories. Data of the present study suggest that the consolidation of intrusive memories in women is modulated by genetic, neurobiological and psychological factors, but is not influenced by oxytocin. Trial registration: NCT03875391.