Feedback-Based Treatments for Eating Disorders and Related Symptoms: A Systematic Review of the Literature

Evaluation of a manualised neurofeedback training in psychosomatic-psychotherapeutic outpatient treatment (Neuro-pp-out): study protocol for a clinical mixed-methods pilot study

INTRODUCTION

Electroencephalographic neurofeedback (NFB), as a non-invasive form of brainwave training, has been shown to be effective in the treatment of various mental health disorders. However, only few results regarding manualised and standardised NFB trainings exist. This makes comparison as well as replication of studies difficult. Therefore, we developed a standard manual for NFB training in patients with mental health disorders attending a psychosomatic outpatient clinic. The current study aims at investigating the conduction of a standardised manual for NFB training in patients with mental health disorders. If successful, the study provides new opportunities to investigate NFB in a more controlled and comparable manner in clinical practice.

METHODS AND ANALYSIS

30 patients diagnosed with a mental health disorder will be included. After the educational interview, patients will undergo baseline diagnostics (T0). The subsequent intervention consists of 10 sessions of NFB training aiming at increasing sensorimotor rhythm and alpha-frequency amplitudes and decreasing theta-frequency and high beta-frequency amplitudes to induce relaxation and decrease subjective stress. All patients will undergo a post-treatment diagnostic assessment (T1) and a follow-up assessment 8 weeks following the closing session (T2). Changes in amplitude bands (primary outcome) will be recorded with electroencephalography during pre-assessments, post-assessments and follow-up assessments and during NFB sessions. Physiological (respiratory rate, blood volume pulse, muscle tension) and psychometric parameters (distress, perceived stress, relaxation ability, depressive and anxiety symptoms, insomnia, self-efficacy and quality of life) will be assessed at T0, T1 and T2. Moreover, satisfaction, acceptance and usability will be assessed at T1 after NFB training. Further, qualitative interviews about the experiences with the intervention will be conducted with NFB practitioners 6 months after the study starts. Quantitative data will be analysed using repeated measures analysis of variance as well as mediation analyses on mixed linear models. Qualitative data will be analysed using Mayring's content analysis.

ETHICS AND DISSEMINATION

The study was approved by the ethics committee of the Medical Faculty of the University of Duisburg-Essen (23-11140-BO) and patient enrolment began in April 2023. Before participation, written informed consent by each participant will be required. Results will be published in peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

Prospectively registered on 28 March 2023 in the German clinical trials register, DRKS00031497.

Near-infrared spectroscopy and electroencephalography neurofeedback for binge-eating disorder: an exploratory randomized trial

BACKGROUND

Binge-eating disorder (BED) co-occurs with neurobehavioral alterations in the processing of disorder-relevant content such as visual food stimuli. Whether neurofeedback (NF) directly targeting them is suited for treatment remains unclear. This study sought to determine feasibility and estimate effects of individualized, functional near-infrared spectroscopy-based real-time NF (rtfNIRS-NF) and high-beta electroencephalography-based NF (EEG-NF), assuming superiority over waitlist (WL).

METHODS

Single-center, assessor-blinded feasibility study with randomization to rtfNIRS-NF, EEG-NF, or WL and assessments at baseline (t0), postassessment (t1), and 6-month follow-up (t2). NF comprised 12 60-min food-specific rtfNIRS-NF or EEG-NF sessions over 8 weeks. Primary outcome was the binge-eating frequency at t1 assessed interview-based. Secondary outcomes included feasibility, eating disorder symptoms, mental and physical health, weight management-related behavior, executive functions, and brain activity at t1 and t2.

RESULTS

In 72 patients (intent-to-treat), the results showed feasibility of NF regarding recruitment, attrition, adherence, compliance, acceptance, and assessment completion. Binge eating improved at t1 by -8.0 episodes, without superiority of NF v. WL (-0.8 episodes, 95% CI -2.4 to 4.0), but with improved estimates in NF at t2 relative to t1. NF was better than WL for food craving, anxiety symptoms, and body mass index, but overall effects were mostly small. Brain activity changes were near zero.

CONCLUSIONS

The results show feasibility of food-specific rtfNIRS-NF and EEG-NF in BED, and no posttreatment differences v. WL, but possible continued improvement of binge eating. Confirmatory and mechanistic evidence is warranted in a double-blind randomized design with long-term follow-up, considering dose-response relationships and modes of delivery.

Neurofeedback strategies in binge-eating disorder as predictors of EEG-neurofeedback regulation success

Introduction

Treatment options such as neurofeedback (NF) that directly target the link between aberrant brain activity patterns and dysfunctional eating behaviors in binge-eating disorder (BED) are emerging. However, virtually nothing is known about mental strategies used to modulate food-specific brain activity and the associated brain-based or subjective success of specific strategies. This study firstly investigated the use of mental strategies in response to individually appetitive food cues in adults with BED and overweight or obesity based on a randomized-controlled trial providing electroencephalography (EEG)- or real-time functional near-infrared spectroscopy (rtfNIRS)-NF to BED.

Methods

Strategy reports written by participants were classified with qualitative content analysis. Additionally, the mental strategies employed by the N = 23 patients who received EEG-NF targeting the reduction of fronto-central high beta activity were analyzed quantitatively through their link with subjective and EEG-NF regulation success.

Results

The following eight categories, ordered by frequency in descending order, were found: "Behavior," "Imagination," "Emotion," "Distraction," "Thought," "Concentration," "Self-Talk" and "No Strategy." Linear mixed models revealed "Imagination," "Behavior," and "Thought" strategies as positive predictors of EEG-NF regulation success (defined as high beta activity during regulation beneath the baseline), and "Concentration" as a negative predictor of subjective (i.e., self-reported) NF regulation success.

Discussion

In conclusion, our study offers a classification system that may be used in future studies assessing strategy use for regulating food-related responses in patients with BED and associated overweight/obesity, providing valuable information on potential benefits of specific strategies and transferability to situations outside the NF treatment.

Psychological and Medical Treatments for Binge-Eating Disorder: A Research Update

Binge-eating disorder (BED), characterized by recurrent binge eating in the absence of regular weight-compensatory behaviors, is the most common eating disorder, associated with pronounced mental and physical sequelae. An increasing body of research documents the efficacy of diverse approaches to the treatment of this disorder, summarized in meta-analyses. This research update narratively reviewed randomized-controlled trials (RCTs) on the psychological and medical treatment of BED published between January 2018 to November 2022, identified through a systematic literature search. A total of 16 new RCTs and 3 studies on previous RCTs providing efficacy- and safety-related data were included. Regarding psychotherapy, confirmatory evidence supported the use of integrative-cognitive therapy and, with lower effects, brief emotion regulation skills training for binge eating and associated psychopathology. Behavioral weight loss treatment was revealed to be efficacious for binge eating, weight loss, and psychopathology, but its combination with naltrexone-bupropion did not augment efficacy. New treatment approaches were explored, including e-mental-health and brain-directed treatments, mostly targeting emotion and self-regulation. Additionally, different therapeutic approaches were evaluated in complex stepped-care models. In light of these advances, future research is necessary to further optimize effects of evidence-based treatments for BED, through improvement of existing or development of new treatments, based on mechanistic and/or interventional research, and/or tailoring treatments to personal characteristics in a precision medicine approach.

Implementing biofeedback treatment in a psychosomatic-psychotherapeutic inpatient unit: a mixed methods evaluation of acceptance, satisfaction, and feasibility

Introduction

Feedback-based therapies such as biofeedback have a benefit in patients with mental health disorders. While biofeedback is heavily researched in outpatient settings, it has been rarely investigated in psychosomatic inpatient settings. The implementation of an additional treatment option in inpatient settings holds special requirements. The aim of this pilot study is the evaluation of additional biofeedback treatment in an inpatient psychosomatic-psychotherapeutic unit to derive clinical implications and recommendations for the future implementation of biofeedback offers.

Methods

The evaluation of the implementation process was investigated using a convergent parallel mixed methods approach (following MMARS guidelines). Quantitative questionnaires measured patients' acceptance and satisfaction with biofeedback treatment after receiving 10 sessions in addition to treatment as usual. After 6 months during implementation, qualitative interviews were conducted with biofeedback practitioners, i.e., staff nurses, examining acceptance and feasibility. Data analysis was conducted using either descriptive statistics or Mayring's qualitative content analysis.

Results

In total, 40 patients and 10 biofeedback practitioners were included. Quantitative questionnaires revealed high satisfaction and acceptance in patients regarding biofeedback treatment. Qualitative interviews showed high acceptance in biofeedback practitioners but revealed several challenges that were encountered during the implementation process, e.g., increased workload due to additional tasks, organizational and structural difficulties. However, biofeedback practitioners were enabled to expand their own competencies and take over a therapeutic part of the inpatient treatment.

Discussion

Even though patient satisfaction and staff motivation are high, the implementation of biofeedback in an inpatient unit requires special actions to be taken. Not only should personnel resources be planned and available in advance of implementation but also be the workflow for biofeedback practitioners as easy and quality of biofeedback treatment as high as possible. Consequently, the implementation of a manualized biofeedback treatment should be considered. Nevertheless, more research needs to be done about suitable biofeedback protocols for this patient clientele.

Sensor Technology and Intelligent Systems in Anorexia Nervosa: Providing Smarter Healthcare Delivery Systems

Ubiquitous technology, big data, more efficient electronic health records, and predictive analytics are now at the core of smart healthcare systems supported by artificial intelligence. In the present narrative review, we focus on sensing technologies for the healthcare of Anorexia Nervosa (AN). We employed a framework inspired by the Interpersonal Neurobiology Theory (IPNB), which posits that human experience is characterized by a flow of energy and information both within us (within our whole body), and between us (in the connections we have with others and with nature). In line with this framework, we focused on sensors designed to evaluate bodily processes (body sensors such as implantable sensors, epidermal sensors, and wearable and portable sensors), human social interaction (sociometric sensors), and the physical environment (indoor and outdoor ambient sensors). There is a myriad of man-made sensors as well as nature-based sensors such as plants that can be used to design and deploy intelligent systems for human monitoring and healthcare. In conclusion, sensing technologies and intelligent systems can be employed for smarter healthcare of AN and help to relieve the burden of health professionals. However, there are technical, ethical, and environmental sustainability issues that must be considered prior to implementing these systems. A joint collaboration of professionals and other members of the society involved in the healthcare of individuals with AN can help in the development of these systems. The evolution of cyberphysical systems should also be considered in these collaborations.

Interactions between emotions and eating behaviors: Main issues, neuroimaging contributions, and innovative preventive or corrective strategies

Emotional eating is commonly defined as the tendency to (over)eat in response to emotion. Insofar as it involves the (over)consumption of high-calorie palatable foods, emotional eating is a maladaptive behavior that can lead to eating disorders, and ultimately to metabolic disorders and obesity. Emotional eating is associated with eating disorder subtypes and with abnormalities in emotion processing at a behavioral level. However, not enough is known about the neural pathways involved in both emotion processing and food intake. In this review, we provide an overview of recent neuroimaging studies, highlighting the brain correlates between emotions and eating behavior that may be involved in emotional eating. Interaction between neural and neuro-endocrine pathways (HPA axis) may be involved. In addition to behavioral interventions, there is a need for a holistic approach encompassing both neural and physiological levels to prevent emotional eating. Based on recent imaging, this review indicates that more attention should be paid to prefrontal areas, the insular and orbitofrontal cortices, and reward pathways, in addition to regions that play a major role in both the cognitive control of emotions and eating behavior. Identifying these brain regions could allow for neuromodulation interventions, including neurofeedback training, which deserves further investigation.

Interoceptive Awareness and Anorexia Nervosa: When Emotions Influence the Perception of Physiological Sensations

ABSTRACT

Anorexia nervosa (AN) is related to difficulties in emotion regulation, including a deficit in interoceptive awareness. The lack of interoceptive awareness is considered a vulnerability involved in the development and maintenance of anorexic symptoms. Surprisingly, no study has been conducted that focuses on these associations in an emotional context. This study measures the interoceptive awareness-using heartbeat self-counting and a sphygmomanometer-of 25 subjects suffering from AN and 25 control subjects, first at rest and then in an emotional situation. The results show that a deficit in interoceptive awareness was observed for the subjects suffering from AN at rest as well as when an emotional context was induced. This study encourages future investigations to focus on the impact of interoceptive deficit in AN to develop as efficient a care regimen as possible for these subjects.

Effects of real-time continuous glucose monitoring in type 1 diabetes: a meta-analysis of randomized controlled trials

AIMS

Self-monitoring of blood glucose (SMBG) represented a major breakthrough in the treatment of type 1 diabetes. The aim of the present meta-analysis is to assess the effect of continues glucose monitoring (CGM) and flash glucose monitoring (FGM), on glycemic control in type 1 diabetes.

MATERIALS AND METHODS

The present analysis includes randomized clinical trials comparing CGM or FGM with SMBG, with a duration of at least 12 weeks, identified in Medline or clinicaltrials.gov. The principal endpoint was HbA1c at the end of the trial. A secondary endpoint was severe hypoglycemia. Mean and 95% confidence intervals for HbA1c and Mantel-Haenzel odds ratio [MH-OR] for severe hypoglycemia were calculated, using random effect models. A sensitivity analysis was performed using fixed effect models. In addition, the following secondary endpoints were explored, using the same methods: time in range, health-related quality of life, and treatment satisfaction. Separate analyses were performed for trials comparing CGM with SMBG, and those comparing CGM + CSII and SMBG + MDI and CGM-regulated insulin infusion system (CRIS) and CSII + SMBG.

RESULTS

CGM was associated with a significantly lower HbA1c at endpoint in comparison with SMBG (- 0.24 [- 0.34, - 0.13]%); CGM was associated with a significantly lower risk of severe hypoglycemia than SMBG. Treatment satisfaction and quality of life were not measured, or not reported, in the majority of studies. FGM showed a significant reduction in the incidence of mild hypoglycemia and an increased treatment satisfaction, but no significant results are shown in HbA1c. CGM + CSII in comparison with SMBG + MDI was associated with a significant reduction in HbA1c. Only two trials with a duration of at least 12 weeks compared a CRIS with SMBG + CSII; HbA1c between the two treatment arms was not statistically significant (difference in means: - 0.23 [- 0.91; 0.46]%; p = 0.52).

CONCLUSION

GCM compared to SMBG has showed a reduction in HbA1c and severe hypoglycemia in patient with type 1 diabetes. The comparison between CGM + CSII and SMBG + MDI showed a large reduction in HbA1c; it is conceivable that the effects of CSII + CGM on glycemic control additives. The only comparison available between FGM and SMBG was conducted in patients in good control.

The Effects of Neurofeedback on Aging-Associated Cognitive Decline: A Systematic Review

For more than a decade, neurofeedback interventions have been applied with the goal of improving cognitive functions in older adults. Some of these studies have been reviewed, but only in combination with experiments conducted in young adults or with studies seeking to modify functions not related to cognition. The purpose of the present review is to assess whether neurofeedback interventions benefit cognition in elderly adults. We included all neurofeedback studies conducted in older adults, whether healthy or affected by a clinical condition, that attempted to ameliorate any domain of cognition, with no restrictions by publication date. Fourteen studies were eligible for this review. Neurofeedback improved memory in healthy and unhealthy participants mainly when the theta and sensorimotor rhythm (SMR) frequencies were trained. In addition, other cognitive domains benefited from this intervention. Conversely, neurofeedback had no effect on attention processes. Although different studies used markedly different methods, almost all of them reported positive effects of neurofeedback in at least one cognitive domain. New interventions under consideration should be tested using placebo-controlled, double-blind experimental designs with follow-up evaluations.

Electroencephalographic (EEG) alterations in young women with high subclinical eating pathology levels: a quantitative EEG study

PURPOSE

To explore electroencephalographic (EEG) alterations in young women with different eating disorder (ED) psychopathology levels.

METHODS

Thirty-seven young women completed general and ED psychopathology (i.e., the ED Examination Questionnaire; EDE-Q) measures. EEG power spectra data were investigated in two conditions: (a) 5 min of resting state (RS) and (b) 5 min of RS after a single taste of a milkshake (ML-RS). EEG analyses were performed using exact Low-Resolution Electromagnetic Tomography software (eLORETA).

RESULTS

Cluster analysis performed on the EDE-Q responses revealed a group of 17 women with high levels of ED pathology falling into the subclinical (i.e., sub-threshold) EDs category and a group of 20 women with low levels of ED pathology (controls). In the RS conditions, no significant modifications were observed between groups. Compared to controls, women with subclinical EDs showed an increase in theta activity in the parieto-occipital areas in the ML-RS condition. After controlling for body mass index and general psychopathology, theta activity in these brain structures was positively associated with EDE-Q global and subscale (restraint, shape and weight concern) scores.

CONCLUSIONS

Our results may reflect the neurophysiological substrate of ED psychopathology core features like shape/weight concerns. Previous brain imaging and qEEG studies with full-syndrome ED patients also underscored the involvement of parieto-occipital areas in ED pathophysiology. These studies also found brain alterations in the RS condition, not observed here. This is notable given that full-syndrome and subclinical EDs are considered as different manifestations of the same disease along a severity spectrum.

LEVEL OF EVIDENCE

Level V, cross-sectional, electroencephalographic, descriptive study.

The Influence of Physiological and Psychological Learning Mechanisms in Neurofeedback vs. Mental Imagery Against Binge Eating

In biofeedback research, the debate on physiological versus psychological learning has a long tradition and is still relevant today, regarding new developments of biofeedback for behavior modification. Analyzing the role of these learning mechanisms may help improving the protocols and answer the question, whether feedback of physiological functions is necessary to modify a target behavior. We explored the presence and impact of physiological (EEG changes) versus psychological learning (changes in somatic self-efficacy) in a recently developed EEG neurofeedback protocol for binge eating. The protocol targets a reduction of food-cue induced cortical arousal through regulation of EEG high beta activity. In an experimental study accompanying a randomized controlled trial, pre and post treatment EEG measurements were analyzed in a neurofeedback group (n = 18) and an active mental imagery control group without physiological feedback (n = 18). Physiological learning in terms of EEG high beta reduction only occurred in the neurofeedback group. Post treatment, participants with successfully reduced binge eating episodes (≥ 50% reduction) showed lower EEG high beta activity than unsuccessful participants (p = .02) after neurofeedback, but not after mental imagery. Further, lower EEG high beta activity at post-treatment predicted fewer binge eating episodes in neurofeedback only. In mental imagery, somatic self-efficacy predicted treatment success instead of EEG activity. Altogether, the results indicate that physiological changes serve as a specific treatment mechanism in neurofeedback against binge eating. Reducing cortical arousal may improve eating behaviors and corresponding neurofeedback techniques should therefore be considered in future treatments.

Eating Disorders and Obesity: The Challenge for Our Times

Public health concerns largely have disregarded the important overlap between eating disorders and obesity. This Special Issue addresses this neglect and points to how progress can be made in preventing and treating both. Thirteen primary research papers, three reviews, and two commentaries comprise this Special Issue. Two commentaries set the scene, noting the need for an integrated approach to prevention and treatment. The empirical papers and reviews fall into four broad areas of research: first, an understanding of the neuroscience of eating behaviours and body weight; second, relationships between disordered eating and obesity risk; third, new and integrated approaches in treatment; and fourth, assessment. Collectively, the papers highlight progress in science, translational research, and future research directions.