Atypical social cognition processing in bulimia nervosa: an fMRI study of patients thinking of others' mental states.

BACKGROUND: Feeding and eating disorders are severe mental disorders that gravely affect patients' lives. In particular, patients with anorexia nervosa (AN) or bulimia nervosa (BN) appear to have poor social cognition. Many studies have shown the relationship between poor social cognition and brain responses in AN. However, few studies have examined the relationship between social cognition and BN. Therefore, we examined which brain regions impact the ability for social cognition in patients with BN. METHODS: We used task-based functional magnetic resonance imaging (fMRI) to examine brain responses during a social cognition task and the Reading Mind in the Eyes Test (RMET). During the fMRI, 22 women with BN and 22 healthy women (HW) took the RMET. Participants also completed the eating disorder clinical measures Bulimic Investigatory Test, Edinburgh (BITE) and Eating Disorders Examination Questionnaire (EDE-Q), the Patient Health Questionnaire (PHQ-9) measure of depression; and the Generalized Anxiety Disorder (GAD-7) measure of anxiety. RESULTS: No difference was observed in the RMET scores between women with BN and HW. Both groups showed activation in brain regions specific to social cognition. During the task, no differences were shown between the groups in the BOLD signal (p < 0.05, familywise error corrected for multiple comparisons). However, there was a tendency of more robust activation in the right angular gyrus, ventral diencephalon, thalamus proper, temporal pole, and middle temporal gyrus in BN (p < 0.001, uncorrected for multiple comparisons). Moreover, HW showed a positive correlation between RMET scores and the activation of two regions: medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC); however, no significant correlation was observed in women with BN. CONCLUSIONS: While activation in the mPFC and ACC positively correlated to the RMET scores in HW, no correlation was observed in BN patients. Therefore, women with BN might display modulated neural processing when thinking of others' mental states. Further examination is needed to investigate neural processing in BN patients to better understand their social cognition abilities. TRIAL REGISTRATION: UMIN, UMIN000010220. Registered 13 March 2013, https://rctportal.niph.go.jp/s/detail/um?trial_id=UMIN000010220.

Associations between autism spectrum disorder and eating disorders with and without self-induced vomiting: an empirical study.

BACKGROUND: Although approximately 23% of anorexia nervosa (AN) patients have concomitant autism spectrum disorder (ASD), it is clinically difficult to determine ASD coexistence in patients with eating disorders. Restrictive AN is more common in younger patients and self-induced vomiting usually appears during adolescence/young adulthood, in order to prevent gaining weight caused by overeating. However, some patients are tolerant of weight gain even if they start overeating. It is important to understand the essential difference between those who vomit and those who do not vomit. In this study, we hypothesised that the absence of self-induced vomiting may be associated with the presence of ASD and aimed to assess the presence of ASD traits in each eating disorder (EDs). Clarifying this association helps to consider the coexistence of ASD in the clinical setting and can lead to the next detailed ASD evaluation, and as a result, helps to determine the appropriate treatment and support individually. METHODS: We retrospectively evaluated 43 females aged 15-45 years who attended Chiba University Hospital between 2012 and 2016 using the Eating Disorder Examination Questionnaire (EDE-Q) and Autism-Spectrum Quotient (AQ) to quantify the severity of the EDs and to identify whether ASD traits were present. RESULTS: There was no difference in the AQ score between bingeing-purging type AN and restricting type AN. However, there was significant difference in the AQ score between bulimia nervosa and binge EDs (BED). Of the 4 ED subtypes, BED had the highest ASD traits. The non-vomiting group with illness duration < 4 years had a significantly higher AQ communication score than the vomiting group with illness duration ≥4 years. CONCLUSIONS: There was a difference in the AQ score by the presence or absence of self-induced vomiting. The results of this study suggest an association between high scores on AQ and non-vomiting. Thus, evaluation of patients for the absence of self-induced vomiting while assessing them for EDs may help us to understand the association with ASD traits.

Hemodynamic responses in prefrontal cortex and personality characteristics in patients with bulimic disorders: a near-infrared spectroscopy study.

PURPOSE: This study sought to identify the prefrontal cortex hemodynamic response that is dependent on cognitive performance in patients with bulimic disorders (BD), and investigate its association with personality characteristics. METHODS: Nineteen female patients with BD and 23 healthy women were recruited. Their personality characteristics related to eating disorders were examined using a self-reporting questionnaire, namely the eating disorder inventory-2 (EDI-2). Cerebral blood flow response in the prefrontal cortex during the digit span backward task (DSBT) was measured using near-infrared spectroscopy (NIRS). Change in oxygenated hemoglobin concentration (ΔoxyHb), obtained using NIRS, were used as an index of brain activity. Further, the relationship between prefrontal cortical activity and personality characteristics was investigated in patients with BD. RESULTS: The cognitive performance of patients with BD was significantly lower in the DSBT compared with healthy subjects. There was no difference between the groups in ΔoxyHb during the task. Task scores of patients with BD correlated with asceticism and perfectionism. Moreover, the asceticism score was negatively correlated with ΔoxyHb of the bilateral prefrontal cortex in patients with BD. CONCLUSION: The results suggest that cognitive performance and brain activity induced during DSBT might be affected by asceticism in BD patients. LEVEL OF EVIDENCE: III, case-control study.

Internet-Based Cognitive Behavioral Therapy via Videoconference for Patients With Bulimia Nervosa and Binge-Eating Disorder: Pilot Prospective Single-Arm Feasibility Trial.

BACKGROUND: A major problem in providing mental health services is the lack of access to treatment, especially in remote areas. Thus far, no clinical studies have demonstrated the feasibility of internet-based cognitive behavioral therapy (ICBT) with real-time therapist support via videoconference for bulimia nervosa and binge-eating disorder in Japan. OBJECTIVE: The goal of the research was to evaluate the feasibility of ICBT via videoconference for patients with bulimia nervosa or binge-eating disorder. METHODS: Seven Japanese subjects (mean age 31.9 [SD 7.9] years) with bulimia nervosa and binge-eating disorder received 16 weekly sessions of individualized ICBT via videoconference with real-time therapist support. Treatment included CBT tailored specifically to the presenting diagnosis. The primary outcome was a reduction in the Eating Disorder Examination Edition 16.0D (EDE 16D) for bulimia nervosa and binge-eating disorder: the combined objective binge and purging episodes, objective binge episodes, and purging episodes. The secondary outcomes were the Eating Disorders Examination Questionnaire, Bulimic Investigatory Test, Edinburgh, body mass index for eating symptoms, Motivational Ruler for motivation to change, EuroQol-5 Dimension for quality of life, 9-item Patient Health Questionnaire for depression, 7-item Generalized Anxiety Disorder scale for anxiety, and Working Alliance Inventory-Short Form (WAI-SF). All outcomes were assessed at week 1 (baseline) and weeks 8 (midintervention) and 16 (postintervention) during therapy. Patients were asked about adverse events at each session. For the primary analysis, treatment-related changes were assessed by comparing participant scores and 95% confidence intervals using the paired t test. RESULTS: Although the mean combined objective binge and purging episodes improved from 47.60 to 13.60 (71% reduction) and showed a medium effect size (Cohen d=-0.76), there was no significant reduction in the combined episodes (EDE 16D -41; 95% CI -2.089 to 0.576; P=.17). There were no significant treatment-related changes in secondary outcomes. The WAI-SF scores remained consistently high (64.8 to 66.0) during treatment. CONCLUSIONS: ICBT via videoconference is feasible in Japanese patients with bulimia nervosa and binge-eating disorder. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000029426; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000033419.

Increased Subjective Distaste and Altered Insula Activity to Umami Tastant in Patients with Bulimia Nervosa.

The aim of this study was to examine differences in brain neural activation in response to monosodium glutamate (MSG), the representative component of umami, between patients with bulimia nervosa (BN) and healthy women (HW) controls. We analyzed brain activity after ingestion of an MSG solution using functional magnetic resonance imaging (fMRI) in a group of women with BN (n = 18) and a group of HW participants (n = 18). Both groups also provided a subjective assessment of the MSG solution via a numerical rating scale. The BN group subjectively rated the MSG solution lower in pleasantness and liking than the control group, although no difference in subjective intensity was noted. The fMRI results demonstrated greater activation of the right insula in the BN group versus the control group. Compared with the HW controls, the BN patients demonstrated both altered taste perception-related brain activity and more negative hedonic scores in response to MSG stimuli. Different hedonic evaluation, expressed as the relative low pleasing taste of umami tastant and associated with altered insula function, may explain disturbed eating behaviors, including the imbalance in food choices, in BN patients.