CBT Effects on Neural, Physiological, and Attentional Responses in Anorexia Nervosa
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexFemale
Age18-35
SponsorIstanbul Nisantasi University
About this trial
This randomized controlled trial investigates the neurophysiological, physiological, and attentional effects of Cognitive-Behavioral Therapy (CBT) in individuals with restrictive-type anorexia nervosa (AN). The study compares two groups: one receiving a 12-week CBT intervention, and one placed on a waitlist (no active treatment during the study period). All participants undergo pre- and post-intervention assessments using electroencephalography (EEG), galvanic skin response (GSR), and eye-tracking while exposed to visual stimuli related to food, body image, and self-appearance. The primary outcomes include neural changes in attention and emotional processing (P300, LPP, frontal alpha asymmetry), physiological arousal (skin conductance), and visual attention biases (fixation duration and gaze distribution). The aim is to determine whether CBT leads to measurable improvements in neurobiological and attentional mechanisms related to body image disturbance and food-related anxiety in AN, contributing to biomarker-informed psychotherapy approaches.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Female participants aged 18 to 35
Meeting DSM-5 diagnostic criteria for restrictive-type anorexia nervosa
Body Mass Index (BMI) between 15.0 and 18.5
Medically stable to participate in psychological and neurophysiological assessments
Disqualifiers
Current or past diagnosis of bulimia nervosa, binge-eating disorder, or other eating disorders
Presence of comorbid severe psychiatric disorders (e.g., psychosis, bipolar disorder, substance use disorder)
History of neurological illness or traumatic brain injury
Use of psychotropic medication within the last 6 weeks
Trial design
Design model
Parallel
Treatments tested in this trial
Cognitive-Behavioral Therapy
BehavioralManualized 12-week CBT protocol focused on reducing body image disturbance, distorted beliefs about food and appearance, and avoidance behaviors in individuals with anorexia nervosa. The intervention incorporates psychoeducation, cognitive restructuring, emotional regulation, food exposure, and body image work.
Treatment groups
60 Participants
are divided into 2 treatment groupsGroup A: CBT Intervention GroupExperimental treatment 1 intervention
Group B: Waitlist Control GroupNo intervention 0 interventions
Trial outcomes
Primary outcomes
1
Change in EEG P300 amplitude in response to body image stimuli
P300 amplitudes will be extracted from EEG data during visual exposure to body image stimuli. Reduced amplitudes post-CBT are hypothesized to indicate reduced attentional salience and hyperfocus on appearance-related cues. P300 amplitudes will be extracted from EEG data during visual exposure to body image stimuli. Reduced amplitudes post-CBT are hypothesized to indicate reduced attentional salience and hyperfocus on appearance-related cues.
Time frame
aseline and Week 122
Change in Late Positive Potential (LPP) amplitude to body and food stimuli
LPP amplitudes will be measured during viewing of thin, overweight, and food-related images. A reduction post-CBT suggests decreased sustained emotional reactivity to distressing visual input.
Time frame
Baseline and Week 123
Change in frontal alpha asymmetry during self-image viewing
Frontal alpha asymmetry (FAA), computed from EEG data, will be used to index emotional regulation. An increase in left-dominant FAA is expected post-CBT, reflecting enhanced emotional control and positive self-perception.
Time frame
Baseline and Week 124
Change in skin conductance response (SCR) to body and food stimuli
Skin conductance responses will be measured via GSR during visual exposure to self-body, other-body, and food stimuli. Decreased SCR amplitudes post-CBT will indicate reduced physiological arousal and distress.
Time frame
Baseline and Week 12Secondary outcomes
1
Change in Eating Disorder Examination Questionnaire (EDE-Q) scores
The EDE-Q assesses eating disorder symptoms across four subscales: Restraint, Eating Concern, Weight Concern, and Shape Concern. Each item is rated from 0 (no pathology) to 6 (high pathology). Global score ranges from 0 to 6. Higher scores indicate greater eating pathology. A reduction in post-treatment scores indicates improvement in eating disorder symptoms.
Time frame
Baseline and Week 122
Change in Beck Depression Inventory-II (BDI-II) scores
The BDI-II consists of 21 items scored from 0 to 3, yielding a total score between 0 and 63. Higher scores reflect more severe depressive symptoms: 0-13: minimal 14-19: mild 20-28: moderate 29-63: severe A decrease in BDI-II score post-CBT is expected, reflecting reduced depressive symptoms.
Time frame
Baseline and Week 123
Change in Beck Anxiety Inventory (BAI) scores
The BAI includes 21 items rated from 0 to 3, with a total score ranging from 0 to 63. Higher scores indicate more severe anxiety: 0-7: minimal 8-15: mild 16-25: moderate 26-63: severe Post-CBT reductions in BAI scores suggest improved anxiety regulation.
Time frame
Baseline and Week 124
Change in Yale-Brown Obsessive Compulsive Scale - Body Dysmorphic Disorder Version (YBOCS-BDD) scores
The YBOCS-BDD contains 12 items rated from 0 to 4, yielding a total score range of 0 to 48. Higher scores reflect greater severity of body image-related obsessions and compulsions. Scores ≥ 20 are considered moderate to severe. Post-treatment reductions reflect decreased symptom severity.
Time frame
Baseline and Week 12Sponsors and contacts
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Istanbul Nisantasi University
Lead sponsor
Uskudar University
Collaborator
Beykoz University
Collaborator
Source ClinicalTrials.gov