The Collaborative Longitudinal Personality Disorders Study: reliability of axis I and II diagnoses

Both the interrater and test-retest-retest reliability of axis I and axis II disorders were assessed using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and the Diagnostic Interview for DSM-IV Personality Disorders (DIPD-IV). Fair-good median interrater kappa (.40-.75) were found for all axis II disorders diagnosed five times or more, except antisocial personality disorder (1.0). All of the test-retest kappa for axis II disorders, except for narcissistic personality disorder (1.0) and paranoid personality disorder (.39), were also found to be fair-good. Interrater and test-retest dimensional reliability figures for axis II were generally higher than those for their categorical counterparts; most were in the excellent range (> .75). In terms of axis I, excellent median interrater kappa were found for six of the 10 disorders diagnosed five times or more, whereas fair-good median interrater kappa were found for the other four axis I disorders. In general, test-retest reliability figures for axis I disorders were somewhat lower than the interrater reliability figures. Three test-retest kappa were in the excellent range, six were in the fair-good range, and one (for dysthymia) was in the poor range (.35). Taken together, the results of this study suggest that both axis I and axis II disorders can be diagnosed reliably when using appropriate semistructured interviews. They also suggest that the reliability of axis II disorders is roughly equivalent to that reliability found for most axis I disorders.