CBT Effects on Neural, Physiological, and Attentional Responses in Anorexia Nervosa

Anorexia nervosa (AN) is a severe psychiatric disorder characterized by distorted body image, food restriction, and intense fear of weight gain. Despite the effectiveness of Cognitive-Behavioral Therapy (CBT) in targeting maladaptive cognitions and behaviors, its underlying neurophysiological mechanisms remain insufficiently understood. This study aims to evaluate the effects of a 12-week CBT intervention on neural, physiological, and attentional responses in individuals with restrictive-type AN using a randomized controlled trial design.

Sixty female participants (aged 18-35) with restrictive-type AN will be recruited and randomly assigned to one of two groups: a CBT intervention group (n = 30) and a waitlist control group (n = 30). Both groups will undergo baseline and post-intervention assessments using EEG, GSR, and eye-tracking. The CBT intervention will consist of weekly 60-minute sessions for 12 weeks, delivered by trained therapists, and will target body image distortion, cognitive restructuring, exposure to food-related stimuli, emotional regulation, and avoidance behaviors.

During the experimental task, participants will view a series of visual stimuli including (1) self-images (unaltered, altered-thin, altered-overweight), (2) food images (low- vs. high-calorie), and (3) images of other female bodies (thin vs. normal weight). EEG markers of interest include P300 (attentional salience), Late Positive Potential (LPP; sustained emotional reactivity), and frontal alpha asymmetry (indicative of affect regulation and self-referential processing). It is hypothesized that CBT will lead to reductions in P300 and LPP amplitudes and an increase in left-frontal cortical activity, indicating enhanced emotional control and reduced fixation on thin-ideal stimuli.

GSR will be used to assess physiological arousal in response to distressing stimuli. It is expected that post-CBT participants will exhibit lower skin conductance responses (SCRs) to body and food images, indicating improved autonomic regulation. Eye-tracking data will capture fixation durations and gaze patterns. Participants in the CBT group are expected to show less visual attention toward "problematic" body areas (waist, stomach, thighs) and reduced avoidance of high-calorie food images compared to the waitlist group.

Participants will also complete standardized psychometric instruments including the Eating Disorder Examination Questionnaire (EDE-Q), Beck Depression Inventory-II (BDI-II), Beck Anxiety Inventory (BAI), the Yale-Brown Obsessive-Compulsive Scale for Body Dysmorphic Disorder (YBOCS-BDD), and the Cognitive Emotion Regulation Questionnaire (CERQ) at both time points.

This trial will provide critical insights into the neurophysiological and attentional mechanisms of CBT in AN, aiming to identify objective biomarkers of therapeutic change. Results may inform precision-based treatment models and support the development of digitally enhanced or neuromodulation-augmented therapies for eating disorders.

• Change in Eating Disorder Examination Questionnaire (EDE-Q) scores [Срок оценки: Baseline and Week 12]
• Change in Beck Depression Inventory-II (BDI-II) scores [Срок оценки: Baseline and Week 12]
• Change in Beck Anxiety Inventory (BAI) scores [Срок оценки: Baseline and Week 12]
• Change in Yale-Brown Obsessive Compulsive Scale - Body Dysmorphic Disorder Version (YBOCS-BDD) scores [Срок оценки: Baseline and Week 12]
• Change in Cognitive Emotion Regulation Questionnaire (CERQ) scores [Срок оценки: Baseline and Week 12]
• Change in subjective distress ratings on Visual Analog Scale (VAS) [Срок оценки: Immediately after the experimental task at both baseline and Week 12]