Effects of Intranasal Oxytocin on the Interpretation and Expression of Emotions in Anorexia Nervosa

Could intranasal oxytocin enhance the effects of psychotherapy in individuals with mental disorders? A systematic review and meta-analysis

Interest in the therapeutic potential of oxytocin for the treatment of mental health disorders, especially those involving social dysfunction, has increased considerably in recent years. To date, most studies have only evaluated oxytocin as monotherapy, with highly inconsistent results. A new line of research is exploring the effects of combining oxytocin with psychotherapy. The aim of the present review was to evaluate the therapeutic effects of intranasal oxytocin combined with psychotherapy in individuals with psychiatric disorders. Only randomized clinical trial design was eligible for inclusion. A search of relevant databases yielded 2480 articles published through April 30, 2024. Of these, 13 trials (518 participants) were included in this review and 4 of them in a meta-analysis. The trials evaluated a range of different psychotherapeutic interventions, oxytocin doses, and mental disorders. Overall, the trials suggested that combined treatment reduced negative mental representations, decreased stress, and increased therapeutic alliance. Meta-analysis showed that combined treatment significantly reduced depressive symptoms (d= -1.58, 95 % CI: -3.15 to -0.01). However, the treatment with oxytocin had no significant effects on psychiatric symptoms (d= 0.00, 95 % CI: -0.56-0.57) or social functioning (d = 0.21, 95 % CI: -0.07-0.49). Limitations included the heterogeneity and limited sample sizes of the trials. The findings suggest that the combination of intranasal oxytocin and psychotherapy may be an effective therapeutic approach to reduce depressive symptoms in individuals with mental disorders and may improve retention and therapeutic alliance.

The impact of oxytocin on emotion recognition and trust: Does disordered eating moderate these relationships?

OBJECTIVES

The current study aimed to investigate the impact of oxytocin on emotion recognition, trust, body image, affect, and anxiety and whether eating disorder (ED) symptoms moderated any of these relationships.

METHOD

Participants (n = 149) were female university students, who were randomly allocated to receive in a double-blind nature, a single dose of oxytocin intranasal spray (n = 76) or a placebo (saline) intranasal spray (n = 73). Participants were asked to complete an experimental measure of emotion recognition and an investor task aimed to assess trust.

RESULTS

The oxytocin group exhibited better overall performance on the emotion recognition task (especially with recognising positive emotions), and a decline in state positive affect than the control group at post-intervention. However, these effects were not moderated by ED symptom severity, nor were effects found for state anxiety, negative affect, body image and recognising negative emotions in the emotion recognition task.

CONCLUSION

The current findings contribute to the growing literature on oxytocin, emotion recognition and positive affect and suggest that ED pathology does not moderate these relationships. Future research would benefit from examining the efficacy of an oxytocin intervention using a within-subjects, cross-over design, in those with sub-clinical and clinical EDs, as well as healthy controls.

Assessing social cognition in patients with schizophrenia and healthy controls using the reading the mind in the eyes test (RMET): a systematic review and meta-regression

The reading the mind in the eyes test (RMET) - which assesses the theory of mind component of social cognition - is often used to compare social cognition between patients with schizophrenia and healthy controls. There is, however, no systematic review integrating the results of these studies. We identified 198 studies published before July 2020 that administered RMET to patients with schizophrenia or healthy controls from three English-language and two Chinese-language databases. These studies included 41 separate samples of patients with schizophrenia (total n = 1836) and 197 separate samples of healthy controls (total n = 23 675). The pooled RMET score was 19.76 (95% CI 18.91-20.60) in patients and 25.53 (95% CI 25.19-25.87) in controls (z = 12.41, p < 0.001). After excluding small-sample outlier studies, this difference in RMET performance was greater in studies using non-English v. English versions of RMET (Chi [Q] = 8.54, p < 0.001). Meta-regression analyses found a negative association of age with RMET score and a positive association of years of schooling with RMET score in both patients and controls. A secondary meta-analysis using a spline construction of 180 healthy control samples identified a non-monotonic relationship between age and RMET score - RMET scores increased with age before 31 and decreased with age after 31. These results indicate that patients with schizophrenia have substantial deficits in theory of mind compared with healthy controls, supporting the construct validity of RMET as a measure of social cognition. The different results for English versus non-English versions of RMET and the non-monotonic relationship between age and RMET score highlight the importance of the language of administration of RMET and the possibility that the relationship of aging with theory of mind is different from the relationship of aging with other types of cognitive functioning.

The neurohypophyseal hormone oxytocin and eating behaviors: a narrative review

BACKGROUND

The neuropeptide oxytocin (OT) is crucial in several conditions, such as lactation, parturition, mother-infant interaction, and psychosocial function. Moreover, OT may be involved in the regulation of eating behaviors.

METHODS

This review briefly summarizes data concerning the role of OT in eating behaviors. Appropriate keywords and medical subject headings were identified and searched for in PubMed/MEDLINE. References of original articles and reviews were screened, examined, and selected.

RESULTS

Hypothalamic OT-secreting neurons project to different cerebral areas controlling eating behaviors, such as the amygdala, area postrema, nucleus of the solitary tract, and dorsal motor nucleus of the vagus nerve. Intracerebral/ventricular OT administration decreases food intake and body weight in wild and genetically obese rats. OT may alter food intake and the quality of meals, especially carbohydrates and sweets, in humans.

DISCUSSION

OT may play a role in the pathophysiology of eating disorders with potential therapeutic perspectives. In obese patients and those with certain eating disorders, such as bulimia nervosa or binge/compulsive eating, OT may reduce appetite and caloric consumption. Conversely, OT administered to patients with anorexia nervosa may paradoxically stimulate appetite, possibly by lowering anxiety which usually complicates the management of these patients. Nevertheless, OT administration (e.g., intranasal route) is not always associated with clinical benefit, probably because intranasally administered OT fails to achieve therapeutic intracerebral levels of the hormone.

CONCLUSION

OT administration could play a therapeutic role in managing eating disorders and disordered eating. However, specific studies are needed to clarify this issue with regard to dose-finding and route and administration time.

The use of intranasal oxytocin in the treatment of eating disorders

Oxytocin (OXT) is a hypothalamic peptide that plays a number of roles in the body, being involved in labor and lactation, as well as cognitive-emotional processes and social behavior. In recent years, knowledge of the physiology of OXT has been repeatedly used to explore its potential role in the treatment of numerous diseases, identifying a significant role for OXT in appetite regulation, eating behavior, weight regulation, and food-related beliefs. In this review we provide an overview of publications on this topic, but due to the wealth of research, we have limited our focus to studies based on the use of intranasal OXT in psychiatric diseases, with a particular focus on the role of oxytocin in eating disorders and obesity. Accumulating evidence that OXT intranasal supplementation may provide some therapeutic benefit seems promising. In individuals with autistic spectrum disorders (ASD) and schizophrenia, OXT may affect core deficits, improving social cognition and reducing symptom severity in schizophrenia. Dysregulation of serum and CSF OXT levels, as well as polymorphisms of its genes, may affect emotion perception in patients with eating disorders and correlate with co-occurring depressive and anxiety disorders. Nevertheless, there are still many critical questions regarding the pharmacokinetics and pharmacodynamics of intranasal OXT that can only be answered in larger randomized controlled trials.

Pharmacotherapy, alternative and adjunctive therapies for eating disorders: findings from a rapid review

BACKGROUND

The current review broadly summarises the evidence base for pharmacotherapies and adjunctive and alternative therapies in the treatment of eating disorders and disordered eating.

METHODS

This paper forms part of a Rapid Review series examining the evidence base in the field of eating disorders. This was conducted to inform the Australian National Eating Disorder Research and Translation Strategy 2021-2030. ScienceDirect, PubMed and Ovid/Medline were searched for included studies published between 2009 and 2021 in English. High-level evidence such as meta-analyses, large population studies and randomised control trials were prioritised, and grey literature excluded. Data from included studies relating to pharmacotherapy, and to adjunctive and alternative therapies in eating disorders, were synthesised and disseminated in the current review.

RESULTS

A total of 121 studies were identified, relating to pharmacotherapy (n = 90), adjunctive therapies (n = 21) and alternative therapies (n = 22). Some of the identified studies involved combinations of the above (e.g. adjunctive pharmacotherapy). Evidence of efficacy of interventions across all three categories was very limited with few relevant high quality clinical trials. There was a particular scarcity of evidence around effective treatments for anorexia nervosa (AN). With treatment of bulimia nervosa (BN), fluoxetine has exhibited some efficacy leading to regulatory approval in some countries. With binge eating disorder (BED), recent evidence supports the use of lisdexamfetamine. Neurostimulation interventions show some emerging efficacy in the treatment of AN, BN and BED but some, such as deep brain stimulation can be highly invasive.

CONCLUSION

Despite widespread use of medications, this Rapid Review has identified a lack of effective medications and adjunctive and alternative therapies in the treatment of EDs. An intensification of high-quality clinical trial activity and drug discovery innovation are required to better assist patients suffering from EDs.

Affective cognition in eating disorders: a systematic review and meta-analysis of the performance on the "Reading the Mind in the Eyes" Test

BACKGROUND

The Reading the Mind in the Eyes Test (RMET) is listed in the National Institute of Mental Health's Research Domain Criteria as a tool apt to measure the understanding of others' mental states. People diagnosed with anorexia nervosa (AN) showed poorer performances on the RMET than healthy controls. Less data are available concerning other eating disorders.

METHODS

Systematic review of four major databases from inception to July 15, 2021 following the PRISMA guidelines. Meta-analysis of cross-sectional observational studies comparing the scores of the RMET between patients with eating disorders and age- and-gender matched control groups.

RESULTS

Out of 21 studies, we retrieved 29 independent samples of patients diagnosed with an eating disorder. Patients with active AN (n = 580) showed worse performances on the RMET than controls (n = 1019). Year of publication accounted for 61% of the (substantial: I2 = 81%) heterogeneity in the meta-analysis. Earlier studies were more likely to find worse performances on the RMET of patients with active AN than later studies. Patients with bulimia nervosa (n = 185) performed poorly as compared to controls (n = 249), but the results were not statistically significant on the random-effect model. Obese patients with binge-eating disorder (n = 54) did not differ on the RMET from obese controls (n = 52). Patients with eating disorder not otherwise specified (n = 57) showed minimal differences compared to controls (n = 96). Study quality was good in six studies only.

CONCLUSIONS

Patients with eating disorders do not suffer from an impaired understanding of others' mental states, except for a still-to-be-identified subgroup of patients with active AN.

LEVEL OF EVIDENCE

I, systematic review and meta-analysis.

OXTR DNA methylation differentiates men on the obesity spectrum with and without binge eating disorder

BACKGROUND

The neuropeptide oxytocin (OXT) plays a role in the regulation of eating behavior and metabolism. OXT functioning is altered in patients with eating and weight disorders, and a variant of the oxytocin receptor gene (OXTR) has been associated with impulsive eating behavior as it is seen in patients with binge eating disorder (BED). Gene × environment interactions could play a role in BED. One mechanism mediating this interaction is the epigenetic alteration of gene expression. We therefore investigated if DNA methylation of the OXTR differs between individuals with obesity depending on a comorbid BED. We analyzed DNA methylation of the OXTR in peripheral blood of 227 individuals on the obesity spectrum (mean age: 40.3 ± 13.1 yrs; mean BMI: 38.6 ± 7.3 kg/m²), 130 of which were diagnosed with BED.

RESULTS

There were no overall differences in OXTR methylation between participants with and those without BED (p > 0.05), while both subgroups were comparable regarding age and body mass index (BMI), but significantly differed in sex distribution (p = 0.035). We found no relationship between mean DNA methylation and BMI or self-reported eating disorder (ED) pathology. Analyzing potential sex differences revealed a significantly lower OXTR DNA methylation in male participants with BED as compared to those without BED (p = 0.017). No such difference was found in the female subsample (p > 0.05).

CONCLUSIONS

Clinically significant binge eating pathology might be associated with lower OXTR DNA methylation exclusively in males. The differential DNA methylation of OXTR in males with BED supports the view that BED represents a phenotype within the obesity spectrum that is characterized by specific vulnerability factors. A better understanding of the epigenetic underpinnings of the OXT system might contribute to the refinement of OXT administration approaches as potential interventions in eating and weight disorders.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Role of Emotion Regulation in Eating Disorders: A Network Meta-Analysis Approach

Background

Previous theoretical models and reviews have documented a strong connection between emotion dysregulation eating disorder (ED) psychopathology among the general and clinical populations. The aim of this review was to build on this previous work by conducting a network meta-analysis to explore associations between adaptive and maladaptive emotion regulation strategies and ED psychopathology trans-diagnostically across the ED spectrum to identify areas of emotion dysregulation that have the strongest association with symptomatology.

Methodology

A total of 104 studies were included in the meta-analysis and correlation coefficient representing the associations between specific emotion regulation strategies and ED symptomatology were extracted. We ran a Bayesian random effects network meta-analysis and the initial network was well-connected with each emotion regulation strategy being linked to at least one other strategy. We also conducted a network meta-regression to explore whether between-study differences in body mass index (BMI), age, and whether the sample consisted of solely female participants explained any possible network inconsistency.

Results

The network meta-analysis revealed that ruminations and non-acceptance of emotions were most closely associated with ED psychopathology. There was no significant network inconsistency but two comparisons approached significance and thus meta-regressions were conducted. The meta-regressions revealed a significant effect of BMI such that the associations between different emotion regulation strategies and ED symptomatology were weaker among those with low BMI.

Discussion

The present findings build on previous work and highlight the role of rumination and difficulties with accepting emotions as key emotion regulation difficulties in EDs. Additionally, the finding that the associations were weaker among ED patients with low BMI may point toward a complex relationship between ED behaviors and emotion regulation. Taken together, our findings call for interventions that target emotion regulation, specifically rumination and difficulties accepting emotions, in the treatment of EDs.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021249996, PROSPERO, identifier: CRD42021249996.

Aberrant neural representation of food stimuli in women with acute anorexia nervosa predicts treatment outcome and is improved in weight restored individuals

Anorexia nervosa (AN) has been associated with altered reward processing. We recently reported greater neural response in secondary visual areas when processing visual food stimuli in acutely underweight AN patients (acAN). In order to examine whether the observed alterations are indicative of acute undernutrition or a potential trait marker of AN, we set out to assess neural responses in acAN and in individuals weight-recovered from AN (recAN). FMRI data were collected from a total of 126 female volunteers, 35 acAN, 33 recAN, and 58 age-matched healthy controls (HC) while they viewed streams of food, social and neutral stimuli. A standard general linear model (GLM) was used to interrogate neural responses to the different stimuli in recAN vs. age-matched HC. Moreover, within-subject multivoxel pattern analyses (MVPA) in the two matched samples (acAN/HC and recAN/HC) were used to estimate neural representation of food vs. neutral, and social vs. neutral stimuli. A multiple regression analysis was conducted to test associations between the accuracy of the neural representation and treatment outcome. The GLM revealed no group differences between recAN and HC. The MVPAs showed greater classification accuracy of food stimuli in the posterior fusiform gyrus in acAN but not recAN. Classification accuracy was associated with better treatment outcome. Our findings suggest that the neural representation of food stimuli is altered in secondary visual areas in acAN and normalizes with weight recovery. Possibly this altered representation reflects attentional engagement motivating food intake, which may promote the recovery process.

Divergent effects of oxytocin on "mind-reading" in healthy males

The neuropeptide oxytocin (OT) has been associated with a broad range of human behaviors, particularly in the domain of social cognition, and is being discussed to play a role in a range of psychiatric disorders. Studies using the Reading The Mind In The Eyes Test (RMET) to investigate the role of OT in mental state recognition reported inconsistent outcomes. The present study applied a randomized, double-blind, cross-over design, and included measures of serum OT. Twenty healthy males received intranasal placebo or OT (24 IU) before performing the RMET. Frequentist and Bayesian analyses showed that contrary to previous studies (Domes et al., 2007; Radke & de Bruijn, 2015), individuals performed worse in the OT condition compared to the placebo condition (p = 0.023, Cohen’s d = 0.55, 95% confidence interval [CI] [0.08, 1.02], BF₁₀ = 6.93). OT effects did not depend on item characteristics (difficulty, valence, intensity, sex) of the RMET. Furthermore, OT serum levels did not change after intranasal OT administration. Given that similar study designs lead to heterogeneous outcomes, our results highlight the complexity of OT effects and support evidence that OT might even interfere with social cognitive abilities. However, the Bayesian analysis approach shows that there is only moderate evidence that OT influences mind-reading, highlighting the need for larger-scale studies considering the discussed aspects that might have led to divergent study results.

Potential shortcomings in current studies on the effect of intranasal oxytocin in Anorexia Nervosa and healthy controls - A systematic review and meta-analysis

RATIONALE

The psychopathology of anorexia nervosa (AN) includes altered social cognition and information processing of fear and anxiety. Oxytocin, a neuromodulating hormone, may influence these functions and could be valuable for the treatment of AN.

OBJECTIVE

The current study aimed at reviewing the effect of intranasal oxytocin (IN-OT) on attentional bias (AB) and emotion recognition (ER) in AN.

METHODS

A systematic literature review was done for free-text and the MeSH-terms: anorexia nervosa, feeding and eating disorders, and oxytocin. Six publications, reporting from 4 unique clinical trials, were included in this review. A meta-analysis was conducted to examine the effects of IN-OT on AB towards food images and ER on healthy controls (HC) and patients with AN.

RESULTS

Overall, IN-OT did not influence AB towards food images (effect size = 0.20 [- 0.16, 0.57], p = 0.28) and had no effect on ER (effect size = - 0.01 [- 0.27, 0.26], p = 0.97) in patients with AN and healthy control (HC) subjects collectively. Assessing HC and AN separately in subgroup analyses did not show any significant effect on AB and ER in neither of the subgroups. All tests were done between 15 and 55 min post-administration of IN-OT, while peak concentration in the cerebrospinal fluid has been determined to be at 75 min.

CONCLUSION

The current level of evidence is moderate showing no effect of IN-OT on AB or ER in AN. However, brain exposure may not have been sufficient which future studies with IN-OT need to ensure by considering dose and dose-to-task interval.

How Can Intranasal Oxytocin Research Be Trusted? A Systematic Review of the Interactive Effects of Intranasal Oxytocin on Psychosocial Outcomes

Over the past two decades, research about the role of oxytocin (OT) in human behavior has grown exponentially. However, a unified theory of OT effects has yet to be developed. Relatedly, growing concerns about the robustness of conclusions drawn in the field have been raised. The current article contributes to this debate by reporting on and discussing key conclusions from a systematic review of published studies addressing the interactive effects of intranasal OT (IN-OT) administration on psychosocial outcomes in a healthy population. The review indicates that (a) tested interactive IN-OT effects were highly heterogeneous; (b) for most published interactions, no replication was attempted; (c) when attempted, replications were largely unsuccessful; (d) significance was unrelated to sample size; (e) statistical power was critically low and unrelated to the rate of significant results; and (f) research practices were characteristic of an exploratory approach. This concerning state of affairs makes it virtually impossible to tease apart true from false interactive IN-OT effects. We provide constructive directions on the basis of this observation and positive predictive value simulations for future research that should help extract true effects from noise and move the IN-OT field forward.

Pharmacotherapeutic strategies for the treatment of anorexia nervosa - too much for one drug?

INTRODUCTION

Anorexia nervosa is a severe psychiatric illness and no medication has been approved for its treatment. This lack of biological treatments requires the development of new directions for pharmacological research.

AREAS COVERED

There is modest but emerging evidence that dopamine D2 and serotonin 1A and 2A receptor agonistic and antagonist medication might be beneficial for weight gain, although the underlying mechanisms are uncertain. Improving quality of life including treating comorbid conditions is an additional important outcome measure, but this has not been well researched. Biological and psychological risk factors together with neurobiological alterations during the illness maintain the disorder 's pathophysiology. Neuroscience research can be used to understand those interactions and advance the research agenda. The authors discuss the above as well as give perspectives on future research.

EXPERT OPINION

If a multidisciplinary approach that includes evidence-based psychotherapy shows unsatisfactory success in weight normalization and cognitive-emotional recovery, then more experimental treatments that are safe and have indicated treatment effectiveness should be tried to augment treatment. Identification and treatment of comorbid conditions to improve quality of life of the patient should also be part of the treatment regimen, even if the effect on weight gain is uncertain.

Interaction between polymorphisms of the oxytocinergic system genes and emotion perception in inpatients with anorexia nervosa

OBJECTIVE

The empirical literature describes the role of the oxytocinergic system in emotion perception (EP). Variants in the oxytocin (OXT) and oxytocin receptor genes have been associated with mental disorders, including anorexia nervosa (AN), that are characterized by difficulties in socioemotional functioning. Our study aimed to examine whether variability within the genes related to OXT pathways may play a role in facial EP in inpatients with AN.

METHOD

Single nucleotide polymorphisms (SNPs) of the following genes: oxytocin receptor (rs2254298, rs53576), OXT (rs6133010), OXT-arginine-vasopressin (rs2740204), CD38 (rs6449197, rs3796863), and human leucyl/cystinylaminopeptidase (rs4869317) were genotyped in 60 AN female inpatients and 60 healthy control females (HCs). Associations between genetic polymorphisms and EP as well as clinical symptoms were examined.

RESULTS

The AN group showed decreased EP abilities compared with HCs. SNPs of rs2740204, rs6133010, and rs53576 were associated with differences in EP in women with AN and in HCs. The SNP of rs4869317 was associated with the level of eating disorders symptoms in HCs.

CONCLUSIONS

The OXT system may be involved in EP difficulties in AN. SNPs within genes related to OXT pathways may influence EP abilities. The leucyl/cystinylaminopeptidase rs4869317 SNP may be involved in the development of eating disorders psychopathology.

Similarities and Differences in Theory of Mind Responses of Patients With Anorexia Nervosa With and Without Autistic Features

Theory of Mind (ToM) is the ability to understand and represent mental states of others, a skill that plays a key role in how we interact with people around us. Difficulties with ToM have been posited as an underlying mechanism for autism and implicated in difficulties faced by those with anorexia nervosa (AN). This study examined, both quantitatively and qualitatively, the responses of women between the ages of 14 and 25 years on the Frith-Happé Triangle Animations, a well-validated test of ToM. Participants were split into healthy controls (HCs), AN patients (AN), and AN patients with high levels of autistic features (AN+ASF). We found no significant quantitative differences between groups in performance on the task. Qualitatively, there were differences between groups such that AN patients, especially those in the AN+ASF group, were more focused on describing the videos than creating narratives, were more negative in their interpretations, and were much more anxious about their performance. These qualitative differences have clinical implications, including that not all AN patients with autistic features should be assumed to have difficulties with ToM.

Cognitive and Affective Empathy in Eating Disorders: A Systematic Review and Meta-Analysis

Background: Recent models of eating disorders (EDs) have proposed social and emotional difficulties as key factors in the development and maintenance of the illness. While a number of studies have demonstrated difficulties in theory of mind and emotion recognition, little is known about empathic abilities in those with EDs. Further, few studies have examined the cognitive-affective empathy profile in EDs. The aim of this systematic review and meta-analysis was to provide a synthesis of empathy studies in EDs, and examine whether those with EDs differ from healthy controls (HC) on self-reported total, cognitive, and affective empathy. Methods: Electronic databases were systematically searched for studies using self-report measures of empathy in ED populations. In total, 17 studies were identified, 14 of which could be included in the total empathy meta-analysis. Eight of the 14 studies were included in the cognitive and affective empathy meta-analyses. Results: Meta-analyses showed that while total empathy and affective empathy scores did not differ between those with anorexia nervosa (AN) and HC, those with AN had significantly lower cognitive empathy scores compared to HCs (small effect size). Meta-analyses of Interpersonal Reactivity Index sub-scores revealed that AN had significantly lower Fantasy scores than HC (small effect size), indicating that those with AN have more difficulty in identifying themselves with fictional characters. Only 3 studies examined empathy in those with bulimia nervosa (BN) or binge eating disorder (BED). Conclusions: The lowered cognitive empathy and intact affective empathy profile found in AN is similar to that found in other psychiatric and neurodevelopmental conditions, such as autism spectrum disorder (ASD). These findings add to the literature characterizing the socio-emotional phenotype in EDs. Future research should examine the influence of comorbid psychopathology on empathy in EDs.

The Neuropeptide Hormone Oxytocin in Eating Disorders

PURPOSE OF REVIEW

The neurohormone oxytocin (OXT) impacts food intake as well as cognitive, emotional, and social functioning-all of which are central to eating disorder (ED) pathology across the weight spectrum. Here, we review findings on endogenous OXT levels and their relationship to ED pathology, the impact of exogenous OXT on mechanisms that drive ED presentation and chronicity, and the potential role of genetic predispositions in the OXT-ED link.

RECENT FINDINGS

Current findings suggest a role of the OXT system in the pathophysiology of anorexia nervosa. In individuals with bulimia nervosa, endogenous OXT levels were comparable to those of healthy controls, and exogenous OXT reduced food intake. Studies in other ED are lacking. However, genetic studies suggest a broad role of the OXT system in influencing ED pathology. Highlighting findings on why OXT represents a potential biomarker of and treatment target for ED, we advocate for a systematic research approach spanning the entire ED spectrum.

Premorbid and Illness-related Social Difficulties in Eating Disorders: An Overview of the Literature and Treatment Developments

BACKGROUND

Social difficulties in eating disorders can manifest as predisposing traits and premorbid difficulties, and/or as consequences of the illness.

OBJECTIVE

The aim of this paper is to briefly review the evidence of social problems in people with eating disorders and to consider the literature on treatments that target these features.

METHOD

A narrative review of the literature was conducted.

RESULTS

People with eating disorders often manifest traits, such as shyness, increased tendency to submissiveness and social comparison, and problems with peer relationships before illness onset. Further social difficulties occur as the illness develops, including impaired social cognition and increased threat sensitivity. All relationships with family, peers and therapists are compromised by these effects. Thus, social difficulties are both risk and maintaining factors of eating disorders and are suitable targets for interventions. Several forms of generic treatments (e.g. interpersonal psychotherapy, cognitive analytic therapy, focal psychodynamic therapy) have an interpersonal focus and show some efficacy. Guided self-management based on the cognitive interpersonal model of the illness directed to both individuals and support persons has been found to improve outcomes for all parties. Adjunctive treatments that focus on specific social difficulties, such as cognitive remediation and emotion skills training and cognitive bias modification have been shown to have a promising role.

CONCLUSION

More work is needed to establish whether these approaches can improve on the rather disappointing outcomes that are attained by currently used treatments for eating disorders.

Intranasal oxytocin in the treatment of anorexia nervosa: Randomized controlled trial during re-feeding

BACKGROUND

Nutritional rehabilitation in anorexia nervosa (AN) is impeded by fear of food, eating and change leading to treatment resistance. Oxytocin (OT) exerts prosocial effects and modulates trust, fear, anxiety and neuroplasticity. The current placebo-controlled RCT examined the effects of intranasal oxytocin (IN-OT) in AN. The aim was to ascertain whether repeated doses of IN-OT enhance treatment outcomes in AN.

METHODS

AN patients self-administered 36 IU IN-OT or placebo daily for 4-6 weeks during hospital treatment. The outcome measures were change in the Eating Disorders Examination (EDE) scale, weight gain, cognitive rigidity, social anxiety, obsessive and autistic symptoms. The effects of the first and last doses of IN-OT were assessed relative to placebo before and after a high-energy afternoon snack, to determine potential dampening of cortisol and anxiety levels by OT.

RESULTS

Weight gain was similar in both groups. The EDE eating concern subscale score was significantly lower after IN-OT treatment as was cognitive rigidity. There were no significant differences in social anxiety or any of the other outcomes at follow-up. After four weeks IN-OT, salivary cortisol levels were significantly lowered in anticipation of an afternoon snack compared to placebo. Morning plasma OT levels did not change after chronic IN-OT or with weight restoration.

CONCLUSION

IN-OT might enhance nutritional rehabilitation in AN by reducing eating concern and cognitive rigidity. Lower salivary cortisol levels in response to IN-OT suggest diminished neuroendocrine stress responsiveness to food and eating. Such effects require replication with inclusion of more sensitive subjective measures.

Oxytocin and Eating Disorders: A Narrative Review on Emerging Findings and Perspectives

BACKGROUND

The hypothalamic neuropeptide oxytocin regulates reproductive behavior and mother-infant interaction, and conclusive studies in humans indicate that oxytocin is also a potent modulator of psychosocial function. Pilot experiments have yielded first evidence that this neuropeptide moreover influences eating behavior.

METHODS

We briefly summarize currently available studies on the involvement of the oxytocin system in the pathophysiology of eating disorders, as well as on the effects of oxytocin administration in patients with these disorders.

RESULTS

Brain administration of oxytocin in animals with normal weight, but also with diet-induced or genetically induced obesity, attenuates food intake and reduces body weight. In normal-weight and obese individuals, acute intranasal oxytocin delivery curbs calorie intake from main dishes and snacks. Such effects might converge with the poignant social and cognitive impact of oxytocin to also improve dysfunctional eating behavior in the therapeutic context. This assumption has received support in first studies showing that oxytocin might play a role in the disease process of anorexia nervosa. In contrast, respective experiments in patients with bulimia nervosa and binge eating disorder are still scarce.

CONCLUSIONS

We propose a framework of oxytocin's role and its therapeutic potential in eating disorders that aims at integrating social and metabolic aspects of its pharmacological profile, and ponder perspectives and limitations of oxytocin use in the clinical setting.

Low oxytocin levels are related to alexithymia in anorexia nervosa

OBJECTIVE

Anorexia nervosa is associated with social-emotional functioning deficits and low levels of the social neurohormone oxytocin, even after weight gain. The relationship between low oxytocin levels and social-emotional functioning impairment has not been studied.

METHOD

We performed a cross-sectional study of 79 women (19 who were less than 85% of ideal body weight [IBW] with anorexia nervosa [AN], 26 who were 90-120% IBW with a history of AN [AN-WR], and 34 who were 90-120% IBW with no eating disorder history [H]). We administered the Eating Disorder Examination-Questionnaire (EDE-Q), Leibowitz Social Anxiety Scale-Self Report (LSAS-SR), Dimensional Assessment of Personality Pathology-Basic Questionnaire (DAPP-BQ; suspiciousness and insecure attachment subscales), and the Toronto Alexithymia Scale (TAS-20). We also analyzed fasting serum oxytocin levels.

RESULTS

Most measures of social-emotional functioning showed impairment in women with AN and AN-WR compared to H. Oxytocin levels were low in AN-WR compared to H. Across groups, low oxytocin levels were associated with difficulty identifying feelings (r = -.45, p = .008) and overall alexithymia (r = -.34, p = .0489).

DISCUSSION

We speculate that low oxytocin levels may contribute to alexithymia in women with anorexia nervosa.

Computerised analysis of facial emotion expression in eating disorders

Background

Problems with social-emotional processing are known to be an important contributor to the development and maintenance of eating disorders (EDs). Diminished facial communication of emotion has been frequently reported in individuals with anorexia nervosa (AN). Less is known about facial expressivity in bulimia nervosa (BN) and in people who have recovered from AN (RecAN). This study aimed to pilot the use of computerised facial expression analysis software to investigate emotion expression across the ED spectrum and recovery in a large sample of participants.

Method

297 participants with AN, BN, RecAN, and healthy controls were recruited. Participants watched film clips designed to elicit happy or sad emotions, and facial expressions were then analysed using FaceReader.

Results

The finding mirrored those from previous work showing that healthy control and RecAN participants expressed significantly more positive emotions during the positive clip compared to the AN group. There were no differences in emotion expression during the sad film clip.

Discussion

These findings support the use of computerised methods to analyse emotion expression in EDs. The findings also demonstrate that reduced positive emotion expression is likely to be associated with the acute stage of AN illness, with individuals with BN showing an intermediate profile.