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.