CBT Effects on Neurophysiological and Psychological Outcomes in Body Dysmorphic Disorder

NCT07016204 | Completed

• 1 other identifier: INUBDD-CBT-2025
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This clinical trial aims to investigate how a specific type of psychotherapy called Cognitive-Behavioral Therapy (CBT) can help people who experience Body Dysmorphic Disorder (BDD). BDD is a mental health condition where individuals become excessively preoccupied with perceived flaws in their physical appearance-flaws that are often unnoticeable to others. This distress can interfere significantly with their social, emotional, and daily functioning. The purpose of this study is to evaluate whether a 12-week CBT program can reduce symptoms of BDD and bring about measurable changes in brain activity, physiological stress responses, and patterns of visual attention when individuals view their own faces or appearance-related images. The researchers will use brainwave recordings (EEG), skin response sensors (GSR), and eye-tracking technology to assess these changes. In addition, participants will complete a set of questionnaires that measure depression, anxiety, emotion regulation, self-esteem, body image beliefs, and self-compassion. Sixty individuals will take part in the study. Thirty will receive CBT sessions once a week for 12 weeks, while the other thirty will be placed on a waitlist and offered treatment later. The study will compare how symptoms and neurophysiological responses change before and after therapy, and whether these changes differ between those who received immediate treatment and those who did not. The researchers hypothesize that CBT will reduce emotional distress, improve emotion regulation, and shift brain and body responses toward healthier patterns. This study will help identify how and why therapy works for BDD, and whether technologies like EEG and eye-tracking can be used to monitor treatment progress.

Conditions

Body Dysmorphic Disorder

Keywords

Cognitive Behavioral Therapy; BDD; Body Image; EEG; Eye-Tracking; GSR

Outcome Measures

Primary Outcomes (3)

• Change in EEG Responses to Appearance-Related Stimuli

  Electroencephalographic (EEG) responses to appearance-related stimuli will be analyzed as a composite neurophysiological outcome, integrating the following components: N170 (early facial processing), P300 (attention allocation), Late Positive Potential - LPP (emotional engagement), and Frontal Alpha Asymmetry (affective regulation). All EEG signals will be recorded using a 14-channel EEG system and processed through synchronized pipelines in iMotions, MATLAB, and R. Each ERP component will be extracted, cleaned, and averaged across trials. Although individual metrics will be analyzed separately for exploratory purposes, the primary analytic approach will treat these variables as a conceptually unified outcome representing neurophysiological change. Statistical comparisons will be conducted using repeated-measures MANOVA and linear mixed-effects modeling to evaluate the impact of CBT over time.

  Baseline, Week 12 (Post-treatment)

• Change in Galvanic Skin Response (GSR) to Appearance-Related Stimuli

  Sympathetic nervous system activity will be measured using Galvanic Skin Response (GSR) during exposure to appearance-related stimuli. The outcome consists of two integrated components: Skin Conductance Level (SCL): baseline tonic arousal Skin Conductance Response (SCR): phasic reactivity to stimuli Both components will be simultaneously recorded using the iMotions platform, preprocessed in MATLAB, and statistically analyzed using R. Though each parameter will be evaluated individually, the primary outcome represents a composite measure of autonomic arousal regulation. CBT is expected to result in decreased SCR amplitude and faster return to baseline SCL, reflecting improved stress regulation.

  Baseline, Week 12 (Post-treatment)

• Change in Visual Attention Patterns During Facial Stimulus Exposure

  Visual attention responses will be measured using eye-tracking during exposure to self-related and appearance-based stimuli. The outcome includes the following integrated metrics: Fixation Duration (ms) Fixation Count (number) Saccade Frequency (number per second) Pupil Dilation (mm) These metrics will be collected via a Gazepoint GP3 eye-tracker, synchronized through iMotions, and analyzed in R and MATLAB. While each measure will be analyzed individually in secondary analyses, this outcome collectively reflects attentional allocation and hypervigilance. CBT is expected to reduce biased attention toward self-perceived flaws and normalize gaze patterns.

  Baseline, Week 12 (Post-treatment)

Secondary Outcomes (5)

• Change in BDD Symptom Severity: Yale-Brown Obsessive Compulsive Scale Modified for Body Dysmorphic Disorder / YBOCS-BDD

  Baseline, Week 12

• Change in Body Image Disturbance Questionaire (BIDQ)

  Baseline, Week 12

• Change in Emotion Regulation Questionaire (ERQ)

  Baseline, Week 12

• Change in Depressive Symptoms (Beck Depression Inventory-II)

  Baseline, Week 12

• Change in Anxiety Symptoms (Beck Anxiety Inventory)

  Baseline, Week 12

Study Arms (2)

Cognitive-Behavioral Therapy (CBT) Group

EXPERIMENTAL

Participants in this arm will receive 12 sessions of manualized Cognitive-Behavioral Therapy (CBT), each lasting 60 minutes, delivered weekly over 12 weeks. The therapy includes psychoeducation, cognitive restructuring, exposure and response prevention (ERP), mindfulness strategies, and attentional retraining related to appearance concerns.

Behavioral: Cognitive-Behavioral Therapy

Waitlist Control Group

NO INTERVENTION

Participants in this arm will receive no active intervention during the 12-week study period but will complete the same neurophysiological and psychometric assessments as the CBT group. After the final follow-up, they will be offered the CBT intervention if desired.

Interventions

Cognitive-Behavioral Therapy BEHAVIORAL

A structured 12-week psychotherapy protocol targeting maladaptive appearance-related beliefs and behaviors in individuals with Body Dysmorphic Disorder (BDD). The intervention involves individual sessions once per week (60 minutes) and incorporates techniques such as psychoeducation, cognitive restructuring, exposure and response prevention (ERP), mindfulness, and attentional retraining.

Cognitive-Behavioral Therapy (CBT) Group

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Diagnosed with Body Dysmorphic Disorder (BDD) according to DSM-5 criteria
• Right-handed (to ensure consistency in EEG lateralization analyses)
• Minimum education level of high school (for questionnaire comprehension)
• Normal or corrected-to-normal vision (for eye-tracking calibration)
• Willingness to participate in all therapy and assessment sessions
• Signed written informed consent

You may not qualify if:

• Current use of psychotropic medication
• Current or past psychotherapy within the last 6 months
• Diagnosis of schizophrenia, bipolar disorder, or substance use disorder
• Neurological disorders (e.g., epilepsy, traumatic brain injury)
• Active suicidal ideation or recent suicide attempt (within past 12 months)
• Pregnancy (due to possible changes in physiological readings)
• Any uncorrected visual impairments or eye conditions preventing eye-tracking
• Presence of metal implants or devices incompatible with EEG recording

Sponsors & Collaborators

• Istanbul Nisantasi University: lead
• Uskudar University: collaborator
• Beykoz University: collaborator

Study Sites (1)

Üsküdar University

Istanbul, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Body Dysmorphic Disorders

Interventions

Cognitive Behavioral Therapy

Condition Hierarchy (Ancestors)

Somatoform Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Behavior Therapy; Psychotherapy; Behavioral Disciplines and Activities

Study Officials

• Selami Varol Ülker, Phd

  Üsküdar University

  STUDY DIRECTOR

• Gökben Hızlı Sayar, Prof

  Üsküdar University

  STUDY CHAIR

• Eda Yılmazer, Phd

  Beykoz University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: No masking will be applied. Participants and researchers are aware of group assignments due to the structure of the intervention.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director

Model Details: Participants with BDD will be randomly assigned to either a 12-week Cognitive-Behavioral Therapy (CBT) group or a waitlist control group. Neurophysiological and psychometric data will be collected at baseline and post-intervention to evaluate treatment effects.

Study Record Dates

• First Submitted: June 2, 2025
• First Posted: June 11, 2025
• Study Start: June 1, 2025
• Primary Completion: October 15, 2025
• Study Completion: November 25, 2025
• Last Updated: April 16, 2026

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, CSR
• Access Criteria: Qualified researchers with a methodologically sound proposal and ethical approval may request access. Requests should be submitted to the corresponding author. Data will be shared through secure institutional platforms, and users must agree to terms of use that ensure participant confidentiality.

Locations

TU (1)