Inter-Rater Reliability of the Structured Interview of DSM-IV Personality (SIDP-IV) in an Adolescent Outpatient Population

Personality disorders (PDs) are a class of mental disorders which are associated with subjective distress, decreased quality of life and broad functional impairment. The presence of one or several PDs may also complicate the course and treatment of symptom disorders such as anxiety and depression. Accurate and reliable means of diagnosing personality disorders are thus crucial to ensuring efficient treatment planning and resource allocation, a fact which is widely acknowledged within the adult mental health field. In adolescents, on the other hand, the consensus view has been that the rapid and discontinuous processes of normal personality development render the construct of PD in adolescents clinically unhelpful and conceptually dubious. However, recent research has established the reliability and validity of the construct, heralding an increased interest in the field, with important conceptual and clinical implications. The present article presents reliability data for the Structured Interview of DSM-IV Personality (SIDP-IV) in an adolescent outpatient population. For this study, 25 interviews conducted by experienced clinicians were blindly re-scored based on sound recordings, which allowed for the calculation of intra-class correlation metrics. The intra-class correlation coefficient for categorical diagnosis of specific personality disorders was found to be 0.876 (95% CI 0.718–0.945); Cohen’s kappa for presence/absence of personality diagnosis was found to be 0.896. The present study found excellent intra-rater reliability for the sample, which suggests that the SIDP-IV is a suitable instrument for assessing personality pathology in adolescent populations.