Yale-Brown Obsessive-Compulsive Scale Modified for Body Dysmorphic Disorder: Factor structure and construct validity of subfactors

The Yale-Brown Obsessive-Compulsive Scale modified for Body Dysmorphic Disorder (BDD-YBOCS) is a semi-structured interview designed to assess the severity of current BDD. The aim of the study was to examine the factor structure and construct validity of the BDD-YBOCS. The sample included 366 adults with BDD who completed the BDD-YBOCS and other measures of BDD severity/impairment, psychiatric distress (i.e., anxiety and depression) and quality of life. Exploratory factor analysis supported two factors that were weakly correlated with each other (r = 0.21) (1) Severity (i.e., time, distress, interference, and avoidance; 31.6% of the variance): and (2) Resistance/Control (i.e., reduced effort to resist symptoms and lack of control over symptoms; 16.7% of the variance). The Severity factor had good internal consistency (α = 0.82) and good construct validity (rs = 0.69-0.81 with BDD severity/impairment; rs = 0.38-0.56 with depression and anxiety; and rs = 0.48-0.53 with functional impairment and quality of life). The Resistance/Control factor had acceptable internal consistency (α = 0.74) but more limited construct validity (rs = 0.27-0.28 with BDD severity/impairment (rs = 0.04-0.20 with depression and anxiety and rs = 0.05-0.14 with functional impairment and quality of life). Implications for the conceptualization and assessment of BDD severity are discussed.