Convergent and discriminant validity of DSM-IV axis II personality disorder criteria in adult outpatients with binge eating disorder.

The study objective was to evaluate the within-category cohesiveness and between-category overlap of DSM-IV axis II personality disorders (PDs) in outpatients with binge eating disorder (BED). Seventy adult outpatients with BED were reliably administered the Diagnostic Interview for DSM-IV Personality Disorders (DIPD-IV). Within-category interrelatedness of the criteria was evaluated by Cronbach's alpha and mean intercriterion correlations (MICs). Between-category criterion overlap was evaluated by examining intercategory mean intercriterion correlations between all pairs of PDs (ICMICs). Cronbach's alpha was .64 to .93 (mean, .77), the MIC was .17 to .52 (mean, .34), and the ICMIC was .11 to .39 (mean, .28). Our findings indicate that in outpatients with BED, the DSM-IV PD criteria sets have convergent validity (acceptable alpha value and MIC). Some degree of discriminant validity also exists: criteria for most DSM-IV PDs correlate better with each other (MIC) than with criteria for other PDs (ICMIC).