Borderline personality disorder in adolescents: evidence in support of the Childhood Interview for DSM-IV Borderline Personality Disorder in a sample of adolescent inpatients.

Empirical evidence is increasing in support of the validity of the construct of borderline personality disorder (BPD) in adolescence. There is growing consensus that the early identification and treatment of emerging borderline traits may be an important focus. However, few diagnostic (questionnaire- or interview-based) measures specifically developed or adapted for adolescents and children exist. The Childhood Interview for DSM-IV Borderline Personality Disorder (CI-BPD) [Zanarini, 2003] is a promising interview-based measure of adolescent BPD. Currently, no studies have explicitly been designed to examine the psychometric properties of the CI-BPD. The aim of the current study was to examine various psychometric properties of the CI-BPD in an inpatient sample of adolescents (n = 245). A confirmatory factor analytic approach was used to examine the internal factor structure of the 9 CI-BPD items. In addition, internal consistency, interrater reliability, convergent validity (with clinician diagnosis and 2 questionnaire-based measures of BPD), and concurrent validity (with Axis I psychopathology and deliberate self-harm) were examined. Similar to several adult studies, the confirmatory factor analytic results supported a unidimensional factor structure for the CI-BPD, indicating that the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria on which the CI-BPD is based constitute a coherent combination of traits and symptoms even in adolescents. In addition, other validity criteria were excellent. Taken together, the current study provides strong evidence for the validity of the CI-BPD for use in adolescents.