Empirically informed symptom severity cutoffs for body dysmorphic disorder.

Area of Science:

• Psychiatry
• Clinical Psychology
• Mental Health Research

Background:

• Body Dysmorphic Disorder (BDD) lacks standardized symptom severity cutoffs, impeding professional communication and patient understanding.
• Current diagnostic tools require clearer benchmarks for classifying BDD symptom intensity.

Purpose of the Study:

• To establish reliable severity cutoffs for Body Dysmorphic Disorder using the Yale-Brown Obsessive-Compulsive Scale Modified for BDD (BDD-YBOCS).
• To provide benchmarks for distinguishing between mild, moderate, severe, and extreme BDD symptom levels.

Main Methods:

• Pooled data from 11 clinical trials and cohort studies, including 804 individuals diagnosed with BDD.
• Utilized receiver-operating characteristic (ROC) analyses to determine BDD-YBOCS score thresholds against the Clinical Global Impressions-Severity (CGI-S) scale.
• Validated the identified cutoffs using a holdout sample of 20% of the participants.

Main Results:

• Established BDD-YBOCS score cutoffs: ≥24 for moderate, ≥30 for severe, and ≥37 for extreme BDD.
• Achieved classification accuracies ranging from 77% to 80% for these cutoffs.
• Found consistent cutoffs across different sexes, age groups, and geographical locations (Europe and US), though performance in the holdout sample was modest (62%).

Conclusions:

• The identified BDD-YBOCS severity cutoffs are valuable for clinical and research applications across diverse populations.
• These cutoffs should supplement, not replace, clinical judgment in individual patient care.
• Further research is needed to define the boundary between subclinical and clinical BDD.