Neural Responses during Social and Self-Knowledge Tasks in Bulimia Nervosa

Diminished Adaptation, Satisfaction, and Neural Responses to Advantageous Social Signals in Anorexia Nervosa and Bulimia Nervosa

BACKGROUND

Development and recurrence of 2 eating disorders (EDs), anorexia nervosa and bulimia nervosa, are frequently associated with environmental stressors. Neurobehavioral responses to social learning signals were evaluated in both EDs.

METHODS

Women with anorexia nervosa (n = 25), women with bulimia nervosa (n = 30), or healthy comparison women (n = 38) played a neuroeconomic game in which the norm shifted, generating social learning signals (norm prediction errors [NPEs]) during a functional magnetic resonance imaging scan. A Bayesian logistic regression model examined how the probability of offer acceptance depended on cohort, block, and NPEs. Rejection rates, emotion ratings, and neural responses to NPEs were compared across groups.

RESULTS

Relative to the comparison group, both ED cohorts showed less adaptation (p = .028, ηp2 = 0.060), and advantageous signals (positive NPEs) led to higher rejection rates (p = .014, ηp2 = 0.077) and less positive emotion ratings (p = .004, ηp2 = 0.111). Advantageous signals increased neural activations in the orbitofrontal cortex for the comparison group but not for women with anorexia nervosa (p = .018, d = 0.655) or bulimia nervosa (p = .043, d = 0.527). More severe ED symptoms were associated with decreased activation of dorsomedial prefrontal cortex for advantageous signals.

CONCLUSIONS

Diminished neural processing of advantageous social signals and impaired norm adaptation were observed in both anorexia nervosa and bulimia nervosa, while no differences were found for disadvantageous social signals. Development of neurocognitive interventions to increase responsivity to advantageous social signals could augment current treatments, potentially leading to improved clinical outcomes for EDs.

Social Processing in Eating Disorders: Neuroimaging Paradigms and Research Domain Organizational Constructs

PURPOSE OF REVIEW

Social and environmental factors have been related to both symptom expression of disordered eating in individuals and changes in the prevalence of eating disorders (EDs) in populations. Neural differences in processing social information may contribute to EDs. This review assesses the evidence for aberrant neural responses during social processing in EDs.

RECENT FINDINGS

This review examines how constructs within the social processing domain have been evaluated by neuroimaging paradigms in EDs, including communication, affiliation, and understanding of both oneself and others. Differences related to social processing in EDs include altered processing for self-relevant stimuli, in the context of identity, valence, expectations, and affiliative relationships. Future work is needed to integrate how differences in processing social stimuli relate to alterations in cognitive control and reward as well as specific disordered eating symptoms.

Elevated Neurobehavioral Responses to Negative Social Interactions in Women With Bulimia Nervosa

BACKGROUND

Bulimia nervosa (BN) is a complex psychiatric illness that includes binge-purge behaviors and a belief that one's value as a person depends on body shape and weight. Social pressure strongly influences the development and maintenance of BN, but how this manifests neurobiologically within an individual remains unknown. We used a computational psychiatry approach to evaluate neural mechanisms underlying social interactions in BN.

METHODS

Behavioral and functional magnetic resonance imaging data were collected from 24 women with BN and 26 healthy comparison women using an iterated social exchange game. Data were sorted round by round based on whether the mathematically computed social signals indicated an improving (positive reciprocity) or deteriorating (negative reciprocity) relationship for each participant.

RESULTS

Social interactions with negative reciprocity resulted in more negative behavioral responses and stronger neural activations in both cortical and subcortical regions in women with BN than healthy comparison women. No behavioral or neural differences were observed for interactions demonstrating positive reciprocity, suggesting a very specific form of psychopathology in BN: amplification of negative self-relevant social interactions. Cortical activations (e.g., temporoparietal junction and dorsolateral prefrontal cortex) did not covary with mood symptoms, while subcortical activations (e.g., amygdala and dorsal striatum) were associated with acute psychopathology.

CONCLUSIONS

These data provide a first step toward a mechanistic neuropsychological model of aberrant social processing in BN, demonstrating how a computational psychiatric approach can elucidate neural mechanisms for complex psychiatric illnesses. Future treatments for BN may include targeting neural regions that support these negative biases in social perceptions.

Neural mechanisms underlying social recognition and theory of mind in adolescent patients with bulimia nervosa and transdiagnostic comparison with anorexia nervosa

INTRODUCTION

Theory of mind (ToM) is important for social interactions and typical development and has been found to be impaired in patients with anorexia nervosa (AN) and bulimia nervosa (BN). Hypoactivation in frontotemporal brain regions seems to be the underlying neural mechanism in AN while whole-brain analyses in BN are lacking.

METHODS

We used the well-validated social recognition task fMRI paradigm to assess ToM in a total of 72 female adolescents (16 BN, 18 AN and 38 matched healthy controls [HC]).

RESULTS

Compared to HC_BN , patients with BN showed hyperactivity during ToM-activity in the right frontal pole, middle temporal gyrus and left temporal pole and differed fundamentally from hypoactivation in these regions observed in patients with AN before and after short-term weight rehabilitation. Interaction and overlap analyses confirmed that similar regions were affected in opposite directions in both diseases. Hyperactivations in BN in the right middle temporal gyrus and right frontal pole were associated with clinical BN-severity markers binging and purging frequency.

DISCUSSION

The hyperactivation in BN suggest different underlying neural mechanisms for ToM compared to AN. Hyperactivity might correspond to a different but also ineffective cognitive style in patients with BN when approaching social interactions. These important transdiagnostic differences are relevant for future brain-targeted therapeutic approaches.

Negative mood induction effects on problem-solving task in women with eating disorders: a multi-method examination

BACKGROUND

The effects of negative affect on problem-solving and its psychophysiological correlates are poorly understood in eating disorder populations.

METHODS

This study examined respiratory sinus arrhythmia (RSA) and skin conductance responses of women with Binge Eating Disorder (BED: n = 56), Anorexia Nervosa (AN: n = 12), Bulimia Nervosa (BN: n = 32), and 24 healthy controls (HCs) at baseline, and then during: a negative mood induction task, an adapted Means Ends Problem-Solving (MEPS) task, and recovery. The MEPS task included four interpersonal scenarios: (1) binge-eating as a solution to stress, (2) job loss, (3) rejection by friends, and (4) by a significant other.

RESULTS

We found that individuals with eating disorders reported less positive mood than HCs and individuals with BN and BED reported more negative mood and greater urges to binge than HCs. After a negative mood induction, women with BED provided significantly less effective problem-solving strategies compared to HCs and women with BN for the binge-eating MEPS scenario. Relative to baseline and the negative mood induction, all participants exhibited significantly higher skin conductance measures throughout the MEPS scenarios and recovery. BED showed significantly lower respiratory sinus arrhythmia (RSA) levels than individuals with BN and HCs throughout the protocol.

CONCLUSIONS

The multimethod findings suggest individuals with BED are likely to have disorder-specific problem-solving difficulties after a negative mood induction.

Qualitative patient experiences from the Self-Blame and Perspective-Taking Intervention for eating disorders

BACKGROUND

Problems in social cognition and social support contribute to eating disorders (ED). Group therapy provides an ideal format to create an experiential learning environment focused on understanding social interactions. This pilot study examined the qualitative content of the participants' experiences in the Self-Blame and Perspective-Taking Intervention (SBPI) for ED.

METHODS

The SBPI was a 4-week group therapy intervention involving art therapy and psychoeducation that focused on social behaviors in ED patients. Participants received surveys immediately after the intervention and at 1 to 4 weeks after the post-intervention. Thematic analyses of qualitative feedback were performed using Braun and Clarke's thematic analysis framework.

RESULTS

Inductive analyses revealed three main themes: (1) Developing self-acceptance through emotional reflection, (2) Changing expectations with neurosocial knowledge, and (3) Bonding and vulnerability in social interactions; all concepts intentionally targeted by the SBPI. Participants varied in their support of a guideline to exclude personal discussion of ED-related cognitions and behaviors in the group.

CONCLUSIONS

As a whole, patients valued the combination of psychosocial education with group experientials focused on social behavior. Positive feedback from the SBPI suggests that adjunctive treatments that target mental-wellness constructs indirectly related to ED pathology may be helpful by allowing patients to see themselves as separable from the illness. Trial registration ClinicalTrials.gov, NCT0487758. Registered 7 May 2021-Retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT04877158 .

Pilot data from the Self-Blame and Perspective-Taking Intervention for eating disorders

Eating disorders (EDs) are characterized by altered eating behaviors and valuation of self-image, as well as difficulty establishing supportive social relationships. This pilot study evaluated feasibility, acceptability, and clinical responses to a novel and brief group-therapy intervention for EDs, the Self-Blame and Perspective-Taking Intervention (SBPI). The SBPI consisted of four sessions of experiential art therapy activities in conjunction with psychoeducation targeting interpersonal attributions and mentalization. Twenty-four outpatient, treatment-seeking women with EDs participated in the SBPI, with 87.5% completing the intervention and 94% rating their participation positively. ED symptoms, depression, anxiety, self-attribution bias, and self-esteem were assessed before (T1) and after participation (N = 20 at T2; N = 18 at T3). Separate repeated measures MANOVAs were performed to assess these clinical and self-concept variables. Relative to baseline, participants demonstrated significant improvements in two all self-concept measures: self-attribution bias, trait self-esteem and state self-esteem at T2. ED, depression, and anxiety symptoms were significantly decreased at both T2 (1-4 weeks post) and T3 (3-5 months post). The SBPI altered self-concept targets acutely and led to sustained clinical improvements. Future work is needed to evaluate how self-concept and social constructs are related to clinical symptom expression in EDs.

Altered regional gray matter volume in Chinese female patients with bulimia nervosa

BACKGROUND

Bulimia nervosa (BN) is a psychiatric disorder with unclear pathophysiology. Several studies have associated BN with structural and functional changes in the brain, but findings have been inconsistent. Here we explored this potential association in a small group of Chinese women with BN.

METHODS

This retrospective study examined 34 women with BN and 34 age-matched healthy controls, all of whom underwent T1-weighted magnetic resonance imaging (MRI). Voxel-based morphometry was carried out to explore alterations in regional grey matter volume (GMV) that may be associated with BN.

RESULTS

The BN group showed smaller GMV in the left medial superior frontal gyrus (SFGmed.L), right superior temporal gyrus (STG.R), right median cingulate and paracingulate gyri (DCG.R), left median cingulate and paracingulate gyri (DCG.L) and left dorsolateral superior frontal gyrus (SFGdor.L). No regions showing GMV increases in BN were identified. The GMV reduction did not correlate with body mass index, duration of illness, or patients' self-esteem or overall self-evaluation. GMV reduction correlated negatively with age in the SFGmed. L (r = - 0.516, P < 0.005), DCG. R (r = - 0.556, P < 0.005), DCG. L (r = - 0.576, P < 0.05) and SFGdor. L (r = - 0.576, P < 0.005).

CONCLUSIONS

Women with BN show reduced GMV in several brain regions, but it is difficult to know whether these changes are the result of BN pathology or of binge-eating and compensatory behavior. These changes may be associated with impaired inhibitory control, body dissatisfaction and emotion dysregulation.

Enhancing activation in the right temporoparietal junction using theta-burst stimulation: Disambiguating between two hypotheses of top-down control of behavioral mimicry

Whereas previous research has focused on the role of the rTPJ when consciously inhibiting mimicry, we test the role of the rTPJ on mimicry within a social interaction, during which mimicking occurs nonconsciously. We wanted to determine whether higher rTPJ activation always inhibits the tendency to imitate (regardless of the context) or whether it facilitates mimicry during social interactions (when mimicking is an adaptive response). Participants received either active or sham intermittent theta-burst stimulation (iTBS: a type of stimulation that increases cortical activation) to the rTPJ. Next, we measured how much participants mimicked the hair and face touching of another person. Participants in the active stimulation condition engaged in significantly less mimicry than those in the sham stimulation condition. This finding suggests that even in a context in which mimicking is adaptive, rTPJ inhibits mimicry rather than facilitating it, supporting the hypothesis that rTPJ enhances representations of self over other regardless of the goals within a given context.

Attention Network Dysfunction in Bulimia Nervosa - An fMRI Study

OBJECTIVE

Recent evidence has suggested an increased rate of comorbid ADHD and subclinical attentional impairments in bulimia nervosa (BN) patients. However, little is known regarding the underlying neural mechanisms of attentional functions in BN.

METHOD

Twenty BN patients and twenty age- and weight-matched healthy controls (HC) were investigated using a modified version of the Attention Network Task (ANT) in an fMRI study. This design enabled an investigation of the neural mechanisms associated with the three attention networks involved in alerting, reorienting and executive attention.

RESULTS

The BN patients showed hyperactivation in parieto-occipital regions and reduced deactivation of default-mode-network (DMN) areas during alerting compared with HCs. Posterior cingulate activation during alerting correlated with the severity of eating-disorder symptoms within the patient group. Conversely, BN patients showed hypoactivation during reorienting and executive attention in anterior cingulate regions, the temporo-parietal junction (TPJ) and parahippocampus compared with HCs, which was negatively associated with global ADHD symptoms and impulsivity, respectively.

DISCUSSION

Our findings demonstrate altered brain mechanisms in BN associated with all three attentional networks. Failure to deactivate the DMN and increased parieto-occipital activation required for alerting might be associated with a constant preoccupation with food or body image-related thoughts. Hypoactivation of executive control networks and TPJ might increase the likelihood of inattentive and impulsive behaviors and poor emotion regulation. Thus, dysfunction in the attentional network in BN goes beyond an altered executive attentional domain and needs to be considered in the diagnosis and treatment of BN.

Alterations in emotion generation and regulation neurocircuitry in depression and eating disorders: A comparative review of structural and functional neuroimaging studies

Major depression and eating disorders (EDs) are highly co-morbid and may share liability. Impaired emotion regulation may represent a common etiological or maintaining mechanism. Research has demonstrated that depressed individuals and individuals with EDs exhibit impaired emotion regulation, with these impairments being associated with changes in brain structure and function. The goal of this review was to evaluate findings from neuroimaging studies of depression and EDs to determine whether there are overlapping alterations in the brain regions known to be involved in emotion regulation, evidence of which would aid in the diagnosis and treatment of these conditions. Our review of the literature suggests that depression and EDs exhibit common structural and functional alterations in brain regions involved in emotion regulation, including the amygdala, ventral striatum and nucleus accumbens, anterior cingulate cortex, insula, and dorsolateral prefrontal cortex. We present preliminary support for a shared etiological mechanism. Future studies should consider manipulating emotion regulation in a sample of individuals with depression and EDs to better characterize abnormalities in these brain circuits.

Neural responses to kindness and malevolence differ in illness and recovery in women with anorexia nervosa

In anorexia nervosa, problems with social relationships contribute to illness, and improvements in social support are associated with recovery. Using the multiround trust game and 3T MRI, we compare neural responses in a social relationship in three groups of women: women with anorexia nervosa, women in long-term weight recovery from anorexia nervosa, and healthy comparison women. Surrogate markers related to social signals in the game were computed each round to assess whether the relationship was improving (benevolence) or deteriorating (malevolence) for each subject. Compared with healthy women, neural responses to benevolence were diminished in the precuneus and right angular gyrus in both currently-ill and weight-recovered subjects with anorexia, but neural responses to malevolence differed in the left fusiform only in currently-ill subjects. Next, using a whole-brain regression, we identified an office assessment, the positive personalizing bias, that was inversely correlated with neural activity in the occipital lobe, the precuneus and posterior cingulate, the bilateral temporoparietal junctions, and dorsal anterior cingulate, during benevolence for all groups of subjects. The positive personalizing bias is a self-report measure that assesses the degree with which a person attributes positive experiences to other people. These data suggest that problems in perceiving kindness may be a consistent trait related to the development of anorexia nervosa, whereas recognizing malevolence may be related to recovery. Future work on social brain function, in both healthy and psychiatric populations, should consider positive personalizing biases as a possible marker of neural differences related to kindness perception.

Neural correlates of eating disorders: translational potential

Eating disorders are complex and serious psychiatric illnesses whose etiology includes psychological, biological, and social factors. Treatment of eating disorders is challenging as there are few evidence-based treatments and limited understanding of the mechanisms that result in sustained recovery. In the last 20 years, we have begun to identify neural pathways that are altered in eating disorders. Consideration of how these pathways may contribute to an eating disorder can provide an understanding of expected responses to treatments. Eating disorder behaviors include restrictive eating, compulsive overeating, and purging behaviors after eating. Eating disorders are associated with changes in many neural systems. In this targeted review, we focus on three cognitive processes associated with neurocircuitry differences in subjects with eating disorders such as reward, decision-making, and social behavior. We briefly examine how each of these systems function in healthy people, using Neurosynth meta-analysis to identify key regions commonly implicated in these circuits. We review the evidence for disruptions of these regions and systems in eating disorders. Finally, we describe psychiatric and psychological treatments that are likely to function by impacting these regions.