An interventional study of Cognitive-Behavioral Therapy in Body Dysmorphic Disorder, sponsored by Istanbul Nisantasi University. Completed at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-16.
Sponsored by Istanbul Nisantasi University · Not applicable, Interventional, and Treatment
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.
Detailed Description Background and Rationale Body Dysmorphic Disorder (BDD) is a chronic and often severely impairing psychiatric disorder characterized by intrusive preoccupations with perceived flaws in one's appearance-flaws that are often imperceptible to others. Individuals with BDD engage in compulsive behaviors such as mirror checking, grooming, or social avoidance, leading to functional impairment and heightened psychological distress. The condition has a high comorbidity with depression and anxiety, and individuals with BDD are at increased risk for suicidality.
Cognitive-Behavioral Therapy (CBT) is the most evidence-based intervention for BDD, targeting cognitive distortions, avoidance behaviors, and emotional dysregulation related to body image. However, despite robust clinical outcomes, the underlying neurophysiological mechanisms of CBT's effectiveness remain insufficiently explored. This trial seeks to address that gap by integrating behavioral symptom change with objective neurophysiological and attentional measures.
This study investigates whether a structured 12-week CBT program produces measurable improvements in brain function, autonomic nervous system response, and attentional bias among individuals with BDD. By combining EEG, GSR, and eye-tracking methods with validated clinical instruments, the research aims to clarify how therapy modulates both the subjective experience and biological correlates of body image disturbance.
Study Design This is a randomized controlled trial with a pre-post design involving two groups: a CBT intervention group and a waitlist control group. Sixty participants aged 18-50 will be recruited. Thirty participants will meet DSM-5 criteria for BDD and will be randomly assigned to either the CBT intervention group (n=15) or the waitlist control group (n=15). An additional healthy control group (n=30) will serve as a normative baseline for neurophysiological comparisons but will not receive any intervention.
The intervention consists of twelve 60-minute weekly CBT sessions focused on psychoeducation, cognitive restructuring, exposure and response prevention (ERP), mindfulness-based emotional regulation techniques, and attentional retraining exercises.
Experimental Protocol
Participants will undergo pre- and post-treatment assessments that include the following:
Neurophysiological Assessment:
EEG recordings will measure event-related potentials (ERPs) such as N170, P300, Late Positive Potential (LPP), and frontal alpha asymmetry.
GSR will capture sympathetic arousal and recovery rates during exposure to appearance-related stimuli.
Eye-tracking will measure fixation duration, pupil dilation, and gaze patterns toward self-perceived flaws and control features.
Stimuli:
Participants will be exposed to images of their own faces (unaltered, neutral, and digitally altered), appearance-related emotional stimuli (e.g., idealized or distorted faces), and non-threatening neutral or positive stimuli.
After each stimulus, they will rate their distress on a Visual Analog Scale (VAS) ranging from 0 to 10.
Psychometric Assessment:
The following validated self-report and clinician-rated scales will be administered at baseline and post-treatment:
Yale-Brown Obsessive-Compulsive Scale Modified for Body Dysmorphic Disorder (BDD-YBOCS): Measures the severity of appearance-related obsessions and compulsions.
Body Image Disturbance Questionnaire (BIDQ): Assesses subjective dissatisfaction and interference caused by perceived appearance flaws.
Emotion Regulation Questionnaire (ERQ): Evaluates cognitive reappraisal and suppression strategies used to manage emotions.
Beck Depression Inventory-II (BDI-II): Measures depressive symptom severity.
Beck Anxiety Inventory (BAI): Measures general anxiety symptoms.
Data Analysis Plan ERP components will be analyzed using repeated-measures ANOVA, focusing on pre-post changes within and between groups. GSR data will be analyzed through paired and independent sample t-tests comparing skin conductance response and recovery. Eye-tracking data will be evaluated using linear mixed-effects models to identify patterns in fixation and gaze shifts.
Changes in psychometric scores will be analyzed via paired t-tests and ANCOVAs. Correlation analyses will examine the association between clinical improvement and physiological markers (e.g., reduced BDD-YBOCS scores and normalized alpha asymmetry). The statistical threshold will be set at p \< .05, and all analyses will follow an intention-to-treat approach.
Scientific and Clinical Contribution This study represents a novel integration of CBT with multi-modal neurophysiological measurement in the context of BDD. It seeks to identify treatment-sensitive biomarkers of emotional and attentional regulation that may serve both diagnostic and therapeutic purposes. If successful, the findings will contribute to the development of personalized CBT interventions guided by real-time physiological feedback and objective clinical markers.
56 studies on the registry are indexed under Body Dysmorphic Disorders; 11 are open to participants now.
This study's enrollment of 60 is above the median of 52 across 44 interventional studies indexed under Body Dysmorphic Disorders.
Browse Body Dysmorphic Disorders studies →Istanbul Nisantasi University is the lead sponsor of 21 studies on the registry; 7 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
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.
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.
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.
Time frame: 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.
Time frame: 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.
Time frame: Baseline, Week 12 (Post-treatment)
Change in BDD Symptom Severity: Yale-Brown Obsessive Compulsive Scale Modified for Body Dysmorphic Disorder / YBOCS-BDD
The Yale-Brown Obsessive Compulsive Scale Modified for Body Dysmorphic Disorder (BDD-YBOCS) is a clinician-administered rating scale that assesses the severity of BDD-related obsessions and compulsions. It includes 12 items, each rated from 0 (no symptoms) to 4 (extreme symptoms), resulting in a total score range of 0 to 48. Higher scores indicate greater symptom severity.
Time frame: Baseline, Week 12
Change in Body Image Disturbance Questionaire (BIDQ)
he Body Image Disturbance Questionnaire (BIDQ) is a 7-item self-report questionnaire that assesses dissatisfaction with appearance, associated distress, and functional impairment. Each item is rated on a Likert scale from 1 to 5, with total scores ranging from 7 to 35. Higher scores reflect more severe body image disturbance.
Time frame: Baseline, Week 12
Change in Emotion Regulation Questionaire (ERQ)
The Emotion Regulation Questionnaire (ERQ) is a 10-item self-report questionnaire measuring two emotion regulation strategies: cognitive reappraisal (6 items) and expressive suppression (4 items). Each item is rated on a 7-point Likert scale from 1 (strongly disagree) to 7 (strongly agree). Subscale scores range from 6 to 42 (reappraisal) and 4 to 28 (suppression). Higher scores reflect greater use of the respective strategy.
Time frame: Baseline, Week 12
Change in Depressive Symptoms (Beck Depression Inventory-II)
The Beck Depression Inventory-II (BDI-II) is a 21-item self-report questionnaire designed to assess the severity of depressive symptoms over the past two weeks. Each item is rated on a 4-point scale from 0 to 3, resulting in a total score range of 0 to 63. Higher scores indicate greater severity of depressive symptoms.
Time frame: Baseline, Week 12
Change in Anxiety Symptoms (Beck Anxiety Inventory)
The Beck Anxiety Inventory (BAI) is a 21-item self-report questionnaire designed to assess the severity of anxiety symptoms experienced during the past week. Each item is scored on a 4-point scale from 0 (not at all) to 3 (severely), yielding a total score range of 0 to 63. Higher scores reflect more severe anxiety symptoms.
Time frame: Baseline, Week 12
Plan to share: Yes — De-identified individual participant data (IPD) that support the primary and secondary outcomes of this trial (including EEG, GSR, eye-tracking data, and psychometric measures such as BDD-YBOCS, BIDQ, ERQ, BDI-II, and BAI) will be shared with qualified researchers upon reasonable request.
Supporting information: Study protocol, Statistical analysis plan, Clinical study report
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.
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Ran from Jun 2025 to primary completion in Oct 2025, 4 months.
Of 26 interventional studies with no phase under Body Dysmorphic Disorders, half reached primary completion within 21 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 34. This study's 4 months is below that.
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This study is completed, as verified in Jun 2025. You cannot join it, but the record below documents what was studied.
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Istanbul Nisantasi University