[Oxytocin: evidence for a therapeutic potential of the social neuromodulator]

The complex role of oxytocin in fear acquisition and generalization

Fear is an adaptive response that protects individuals from potential threats, but when excessive, it can lead to mental health disorders such as generalized anxiety disorder. Oxytocin is a neuromodulator whose effects on fear processing have been explored, although research results are inconsistent. Previous research indicates that administering oxytocin before fear acquisition can enhance fear learning, while studies have suggested a potential for reducing fear generalization when oxytocin is given after fear acquisition. However, few studies have explored the interplay between oxytocin-induced enhanced fear learning and its drug impact on fear generalization afterwards. To investigate this interaction, a double-blind, placebo-controlled study was conducted where oxytocin was administered before fear acquisition to assess its influence on fear generalization during the drug's effect. A total of 54 healthy male participants were recruited, with 29 in the experimental group and 25 in the control group. Participants received intranasal oxytocin 30 minutes before the fear acquisition phase, with the generalization phase occurring 45 minutes after the intranasal oxytocin. Results revealed that oxytocin increased shock expectancy ratings for fear stimuli (compared with safe stimuli) during acquisition and elevated shock expectancy for generalization stimuli in the generalization phase. These findings suggested that oxytocin may increase vigilance towards safe stimuli and contribute to maladaptive generalization when intranasal oxytocin was administered prior to fear acquisition. This study provides new insights into the potential clinical applications of oxytocin for interaction effect of oxytocin-induced enhanced fear learning to both fear acquisition and fear generalization fear-related disorders.

Effects of mind-body therapies on depression among adolescents: a systematic review and network meta-analysis

Background

Depression poses significant threats to adolescents' health globally. Research has shown the potential of mind-body therapies to alleviate depression, but limited studies have directly compared the therapeutic effects of different types of mind-body therapies on adolescent depression and the optimal therapy remain unclear. Therefore, we conducted a systematic review and network meta-analysis of randomized controlled trials that met the inclusion criteria to explore the effectiveness of different types of mind-body therapies as interventions to improve depression among adolescents, and to identify the most effective interventions.

Methods

A comprehensive search of databases including PubMed, EMBASE, Cochrane Library, Web of Science, and Scopus up to January 2024 was conducted to assess the impact of mind-body therapies on depression among adolescents. The risk of bias of the included studies was evaluated using Cochrane Review Manager 5.4. STATA 18.0 was used for network meta-analysis. The node-splitting method was used to test the local inconsistency of the network meta-analysis. Funnel plots and the Egger's test were utilized to assess the potential impact of bias in this study.

Result

This network meta-analysis included 9 randomized controlled trials involving a total of 955 subjects. The results indicated that yoga, dance therapy and Tai Chi were more effective than other mind-body therapies in reducing symptoms of depression among adolescents. Specifically, according to the SUCRA ranking, yoga was rated to be the optimal intervention for adolescents with depression (SCURA: 82.2%), followed by dance therapy (SCURA: 77.5%) and Tai Chi (SCURA: 64.9%).

Conclusion

This study revealed that mind-body therapies have positive effects on improving depression among adolescents. Yoga may be the most effective intervention among the different types of mind-body therapies. However, due to the small sample size of patients included, the certainty of the results was limited to some extent. Therefore, further investigation is necessary to strengthen the evidence base when more relevant studies become available.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024508774.

[Oxytocin in schizophrenia : Evidence for an etiological and therapeutic relevance of the social neuromodulator]

Neurobiological results from animal models as well as biochemical and genetic findings in patients indicate that the oxytocin (OT) system may be dysfunctional in schizophrenia. On this pathogenetic basis transnasally administered OT (tnOT) could be an innovative treatment option for schizophrenia. Experimental data from animal studies are also suggestive of a particular effectiveness in treatment-resistant schizophrenia. To date, clinical data on tnOT treatment of schizophrenia patients does not unequivocally support a general therapeutic effect on the psychopathology but suggests positive effects on higher integrated social cognitive performance, such as empathy and mentalization. In particular, tnOT augmentation of a social cognitive skills training resulted in a marked and lasting treatment effect; however, numerous person- and context-dependent variables can potentially moderate individual effects of OT and may even reverse effects in certain constellations. Most clinical studies so far have not systematically accounted and controlled for these factors with the probable result of larger variance of recorded treatment effects and lower likelihood of ascertaining positive effectiveness. Furthermore, there is still a gap of knowledge on dose response relations and central nervous system (CNS) permeation in man following tnOT administration. This review aims to give a concise overview on the evidence for the etiological relevance of the neurohormone OT and its treatment potential in schizophrenia.

Dyadic Coping and Its Underlying Neuroendocrine Mechanisms - Implications for Stress Regulation

Previous research suggests that neuroendocrine mechanisms underlie inter-individual stress coping in couples. The neuropeptide oxytocin (OT), while regulating stress-sensitive HPA-axis activity might be crucial in this process. The purpose of this study was to examine the impact of dyadic coping abilities and OT on HPA-axis outcomes and constructive behavior during couple conflict. We conducted a secondary analysis of our previous database (Ditzen et al., 2009), assessing the modulating role of dyadic coping and intranasal OT on couple conflict behavior. The data revealed a significant interaction effect of the dyadic coping by oneself score and OT on cortisol responses during couple conflict, suggesting that particularly individuals with low a priori dyadic coping benefit from OT in terms of dampened HPA-activity. The results are in line with previous research suggesting OT’s central role for stress regulation and prosocial behavior. Furthermore, an interaction with dyadic coping indicates adaptations in the sensitivity of the OT system during the individual attachment and relationship history. These data add to the evidence that the neuroendocrine attachment systems influence couple behavior. Future studies of neurobiological mechanisms underlying dyadic coping will be of high relevance for the development of prevention and intervention programs.

Oxytocin differentially modulates pavlovian cue and context fear acquisition

Fear acquisition and extinction have been demonstrated as core mechanisms for the development and maintenance of mental disorders, with different contributions of processing cues vs contexts. The hypothalamic peptide oxytocin (OXT) may have a prominent role in this context, as it has been shown to affect fear learning. However, investigations have focused on cue conditioning, and fear extinction. Its differential role for cue and context fear acquisition is still not known. In a randomized, double-blind, placebo (PLC)-controlled design, we administered an intranasal dose of OXT or PLC before the acquisition of cue and context fear conditioning in healthy individuals (n = 52), and assessed brain responses, skin conductance responses and self-reports (valence/arousal/contingency). OXT compared with PLC significantly induced decreased responses in the nucleus accumbens during early cue and context acquisition, and decreased responses of the anterior cingulate cortex and insula during early as well as increased hippocampal response during late context, but not cue acquisition. The OXT group additionally showed significantly higher arousal in late cue and context acquisition. OXT modulates various aspects of cue and context conditioning, which is relevant from a mechanism-based perspective and might have implications for the treatment of fear and anxiety.

Deciphering the modulatory role of oxytocin in human altruism

Unlike any other species, humans frequently engage in altruistic behaviors by which they increase another individual's welfare even if this implies personal costs. The psychological motives underlying altruistic behaviors remain diverse, ranging from the ability to reciprocate trust and cooperation to bonding and empathizing with family members or even genetically unrelated others. This article explores the neuroendocrine architecture of altruism by emphasizing the crucial role of the evolutionarily highly conserved peptide hormone oxytocin as a modulator of cooperative behaviors including empathy-driven altruism. However, accumulating evidence suggests that oxytocin does not invariably facilitate cooperation but also produces protective or even defensive-aggressive responses in specific social contexts. In addition, we highlight the relevance of message frames as critical determinants of whether the peptide promotes altruism toward prosocial ends.

Oxytocin and Interpersonal Relationships

The neuropeptide oxytocin (OT) has emerged as a potent modulator of diverse aspects of interpersonal relationships. OT appears to work in close interaction with several other neurotransmitter networks, including the dopaminergic reward circuit, and to be dependent on sex-specific hormonal influences. In this chapter, we focus on four main domains of OT and interpersonal relationships, including (1) the protective effect of OT on an individual's ability to withstand stress (i.e., stress buffering), (2) the effect of OT on emotion recognition and empathy, (3) OT's ability to enhance social synchrony and cooperation among individuals, and (4) the effect of OT on an individual's perception of social touch. We then illustrate the connection between OT and loneliness while grieving the loss of a loved one. We finish by discussing the clinical potential of OT, focusing on its potential role as an adjunct to psychotherapy, its enhancement through sex-specific hormonal influences, and the difficulties that present themselves when considering OT as a therapy. Overall, we argue that OT continues to hold strong therapeutic promise, but that it is strongly dependent on internal and external influences, for instance the patient's personal past experiences and interaction with the therapist, in order to provide the best possible therapy.

[Social psychiatry and neurobiology : A long overdue convergence exemplified by schizophrenia]

BACKGROUND

The proliferation of biological psychiatry has greatly increased over the last two decades. With the possibility to carry out brain research using modern technical methods, it seemed that social influencing factors would lose importance in the development of mental diseases; however, in actual fact this does not seem to be justified. It is necessary to overcome this separation, in that social factors are incorporated into a conceptual framework in the development of mental diseases, which simultaneously also takes the results of current neurobiological research into consideration.

OBJECTIVES AND METHODS

The aims of this review article are to summarize the current state of sociopsychiatric research and to emphasize the perspectives of the biological principles and their validity with respect to the social dimensions of psychiatry, as exemplified by schizophrenic disorders. The article presents the options for a biosocial approach in social psychiatry and gives an overview of the currently available literature.

RESULTS AND CONCLUSION

There is an abundance of neurobiological research approaches, which are closely associated with sociopsychiatric topics, such as social cognition. Social psychiatry and biological psychiatry should no longer be considered as diametrically opposed subdisciplines. On the contrary, the options which could emerge from a synthesis must be used in research and clinical practice.

Lower Oxytocin Plasma Levels in Borderline Patients with Unresolved Attachment Representations

Interpersonal problems and affective dysregulation are core characteristics of borderline personality disorder (BPD). BPD patients predominantly show unresolved attachment representations. The oxytocin (OT) system is associated with human social attachment and affiliative behavior, and OT dysregulation may be related to distinct attachment characteristics. Here, we investigated whether attachment representations are related to peripheral OT levels in BPD patients. Twenty-one female BPD patients and 20 age-, gender-, and education-matched healthy controls (HCs) were assessed with clinical scales and measures of interpersonal and attachment-related characteristics, including the Adult Attachment Projective Picture System (AAP). Plasma OT concentrations were measured prior to and during social exclusion in a virtual ball tossing game (Cyberball). The majority of BPD patients (63.2%) but no HCs showed unresolved (disorganized) attachment representations. In this subgroup of patients, baseline OT plasma levels were significantly lower than in BPD patients with organized attachment representations. This pilot study extends previous findings of altered OT regulation in BPD as a putative key mechanism underlying interpersonal dysregulation. Our results provide first evidence that altered OT plasma levels are related to disorganized attachment representations in BPD patients.

Oxytocin Facilitates Pavlovian Fear Learning in Males

In human evolution, social group living and Pavlovian fear conditioning have evolved as adaptive mechanisms promoting survival and reproductive success. The evolutionarily conserved hypothalamic peptide oxytocin is a key modulator of human sociality, but its effects on fear conditioning are still elusive. In the present randomized controlled study involving 97 healthy male subjects, we therefore employed functional magnetic resonance imaging and simultaneous skin conductance response (SCR) measures to characterize the modulatory influence of intranasal oxytocin (24 IU) on Pavlovian fear conditioning. We found that the peptide strengthened conditioning on both the behavioral and neural levels. Specifically, subjects exhibited faster task-related responses and enhanced SCRs to fear-associated stimuli in the late phase of conditioning, which was paralleled by heightened activity in cingulate cortex subregions in the absence of changes in amygdala function. This speaks against amygdalocentric views of oxytocin having pure anxiolytic-like effects. Instead, it suggests that the peptide enables extremely rapid and flexible adaptation to fear signals in social contexts, which may confer clear evolutionary advantages but could also elevate vulnerability for the pathological sequelae of interpersonal trauma.

Oxytocin facilitates the extinction of conditioned fear in humans

BACKGROUND

Current neurocircuitry models of anxiety disorders posit a lack of inhibitory tone in the amygdala during acquisition of Pavlovian fear responses and deficient encoding of extinction responses in amygdala-medial prefrontal cortex circuits. Competition between these two responses often results in a return of fear, limiting control over anxiety. However, one hypothesis holds that a pharmacologic strategy aimed at reducing amygdala activity while simultaneously augmenting medial prefrontal cortex function could facilitate the extinction of conditioned fear.

METHODS

Key among the endogenous inhibitors of amygdala activity in response to social fear signals is the hypothalamic peptide oxytocin. To address the question whether oxytocin can strengthen Pavlovian extinction beyond its role in controlling social fear, we conducted a functional magnetic resonance imaging experiment with 62 healthy male participants in a randomized, double-blind, parallel-group, placebo-controlled design. Specifically, subjects were exposed to a Pavlovian fear conditioning paradigm before receiving an intranasal dose (24 IU) of synthetic oxytocin or placebo.

RESULTS

Oxytocin, when administered intranasally after Pavlovian fear conditioning, was found to increase electrodermal responses and prefrontal cortex signals to conditioned fear in the early phase of extinction and to enhance the decline of skin conductance responses in the late phase of extinction. Oxytocin also evoked an unspecific inhibition of amygdalar responses in both phases.

CONCLUSIONS

Collectively, our findings identify oxytocin as a differentially acting modulator of neural hubs involved in Pavlovian extinction. This specific profile of oxytocin action may open up new avenues for enhancing extinction-based therapies for anxiety disorders.

Social cognition

Social cognition is a major problem underlying deficiencies in interpersonal relationships in several psychiatric populations. And yet there is currently no gold standard for pharmacological treatment of psychiatric illness that directly targets these social cognitive areas. This chapter serves to illustrate some of the most innovative attempts at pharmacological modulation of social cognition in psychiatric illnesses including schizophrenia, borderline personality disorder, autism spectrum disorders, antisocial personality disorder and psychopathy, social anxiety disorder, and posttraumatic stress disorder. Pharmacological modulation includes studies administering oxytocin, ecstasy (MDMA), modafinil, methylphenidate, and D-cycloserine. Furthermore, some background on social cognition research in healthy individuals, which could be helpful in developing future treatments, is provided as well as the potential for each drug as a long-term treatment option.

Effects of social exclusion on emotions and oxytocin and cortisol levels in patients with chronic depression

OBJECTIVE

Patients with chronic depression (CD) experience a high burden of disease, severe co-morbidity, and increased mortality. Although interpersonal dysfunction is a hallmark of CD, the underlying mechanisms are largely unexplored. Oxytocin (OT) has been proposed to play a crucial role in the social deficits of mental disorders and has been found to be dysregulated after social exclusion (ostracism) in patients with borderline personality disorder. This study investigated how social exclusion affects emotions, OT levels, and cortisol (CT) levels in CD patients.

METHOD

Twenty-one patients diagnosed with CD and 21 healthy controls (HC) matched for gender, age, and education underwent repeated neuroendocrine measurements in a standardized laboratory setting while playing Cyberball, a virtual ball-tossing game that mimics a social exclusion situation. Emotional reactions, plasma OT and cortisol levels were assessed at baseline and 5, 15, and 40 min after Cyberball.

RESULTS

At baseline, there were no group differences in OT levels. Immediately after playing Cyberball, plasma OT levels showed divergent changes in CD patients and HC; the difference in direction of change was significant with a reduction in CD patients compared to HC (p = .035*); CT levels did not differ between groups at any time point, but decreased over time. Patients showed more threatened emotional needs and increased negative emotions, especially anger and resentment, and showed higher sensitivity to ambiguous threat of social exclusion than healthy controls.

CONCLUSIONS

CD patients react to ostracism with pronounced negative emotions. The reduction in OT levels in CD patients after social exclusion may contribute to their interpersonal dysfunction and their difficulty in coping adequately with aversive social cues.

Oxytocin facilitates the sensation of social stress

Essentially all social species experience social stress which can be a catalyst for detriments in mental and physical health. The neuropeptide oxytocin (OXT) has been shown to produce anxiolytic and antistress effects, thereby qualifying the OXT system as a promising drug target in the treatment of stress-related disorders. However, recently it has been shown that OXT can have anxiogenic effects as well. In the present study, we used functional magnetic resonance imaging to scan the brains of 60 healthy men while they were exposed to social stress after they received either intranasal OXT (24 IU) or placebo treatment. Although OXT administration did not alter salivary cortisol levels as a surrogate marker of stress axis activity, our participants initially reported an increment in perceived social stress. This behavioral effect was paralleled on the neural level by increased activity in the precuneus and cingulate cortex. Taken together, our results support the hypothesis that OXT can induce a self-referential processing bias which facilitates the sensation of social stress in the absence of altered endocrine responses.

Opposing effects of oxytocin on moral judgment in males and females

Current perspectives on the evolutionary roots of human morality suggest it arose to incentivize social cooperation by promoting feelings of disgust toward selfish behavior, although the underlying neural mechanisms remain unclear. To investigate whether the ancient mammalian neuropeptide oxytocin (OXT) influences self-referential processing in the domains of emotion evaluation and moral decision making, we conducted a pharmaco-functional magnetic resonance imaging (fMRI) and a behavioral experiment involving 157 healthy women and men who were treated with either OXT (24 IU) or placebo (PLC) intranasally. Our results show that OXT facilitated cortical midline responses during self-processing of disgust and selectively promoted self-interest moral judgments in men. In contrast, in women OXT increased the reaction time difference between accepted and rejected moral dilemmas and led them to suppress their self-interest and respond more altruistically for the benefit of others. Taken together, these findings suggest an OXT-related sexual dimorphism in human moral behavior which evolved adaptively to optimize both protection and nurturing of offspring by promoting selfish behavior in men and altruistic behavior in women.

An oxytocin-induced facilitation of neural and emotional responses to social touch correlates inversely with autism traits

Social communication through touch and mutual grooming can convey highly salient socio-emotional signals and has been shown to involve the neuropeptide oxytocin (OXT) in several species. Less is known about the modulatory influence of OXT on the neural and emotional responses to human interpersonal touch. The present randomized placebo (PLC)-controlled within-subject pharmaco-functional magnetic resonance imaging (fMRI) study was designed to test the hypothesis that a single intranasal dose of synthetic OXT (24 IU) would facilitate both neural and emotional responses to interpersonal touch in a context- (female vs male touch) and trait- (autistic trait load) specific manner. Specifically, the experimental rationale was to manipulate the reward value of interpersonal touch independent of the intensity and type of actual cutaneous stimulation administered. Thus, 40 heterosexual males believed that they were touched by either a man or a woman, although in fact an identical pattern of touch was always given by the same female experimenter blind to condition type. Our results show that OXT increased the perceived pleasantness of female, but not male touch, and associated neural responses in insula, precuneus, orbitofrontal, and pregenual anterior cingulate cortex. Moreover, the behavioral and neural effects of OXT were negatively correlated with autistic-like traits. Taken together, this is the first study to show that the perceived hedonic value of human heterosexual interpersonal touch is facilitated by OXT in men, but that its behavioral and neural effects in this context are blunted in individuals with autistic traits.