Internal consistency, intercriterion overlap and diagnostic efficiency of criteria sets for DSM-IV schizotypal, borderline, avoidant and obsessive-compulsive personality disorders

Objective: To evaluate performance characteristics of DSM-IV Personality Di sorders (PDs) criteria. Method: Six hundred and sixty-eight adults recruited for the Collaborative Longitudinal Personality Disorders Study (CLPS) were assessed with diagnost ic interviews. Results: Within-category inter-relatedness was evaluated by Cronbach's alph a and median intercriterion correlations (MIC). Cronbach's alpha ranged fro m 0.47 to 0.87 (median=0.71); seven of the 10 PDs had alphas greater than 0 .70. Between-category criterion overlap was evaluated by 'inter-category' i ntercriterion correlations between all PD pairs (ICMIC). ICMIC values (medi an=0.08) were lower than MIC values (median=0.23). Diagnostic efficiency st atistics (sensitivity, specificity, positive predictive power and negative predictive power were calculated for schizotypal, borderline, avoidant and obsessive-compulsive PDs. Conclusion: DSM-IV PID criteria sets have some convergent validity and disc riminant validity: criteria for individual PDs correlate better with each o ther than with criteria for other PDs. Diagnostic efficiency statistics pro vide guidance regarding usefulness of criteria for inclusion or exclusion.