Borderline personality disorder (BPD) is a common and severe mental disorder that is associated with severe functional impairment and a high suicide rate. BPD is usually associated with other psychiatric and personality disorders, high burden on families and carers, continuing resource utilization, and high treatment costs. BPD has been a controversial diagnosis in adolescents, but this is no longer justified. Recent evidence demonstrates that BPD is as reliable and valid among adolescents as it is in adults and that adolescents with BPD can benefit from early intervention. Consequently, adolescent BPD is now recognized in psychiatric classification systems and in national treatment guidelines. This review aims to inform practitioners in the field of adolescent health about the nature of BPD in adolescence and the benefits of early detection and intervention. BPD diagnosis and treatment should be considered part of routine practice in adolescent mental health to improve these individuals’ well-being and long-term prognosis.

Self-injurious thoughts and behaviors (SITBs) are common in adolescents. While there is no standardized interview in German to assess SITBs to date, the Self-Injurious Thoughts and Behaviors Interview (SITBI) is widely used in English-speaking countries. However, the SITBI has not been validated for the assessment of the recently issued DSM-5 Section 3 diagnoses of nonsuicidal self-injury (NSSI) and suicidal behavior disorder (SBD) yet. In the present study the psychometric properties of the German version of the SITBI (SITBI-G) were assessed. We also evaluated whether SITBI-G is a reliable and valid instrument to establish diagnoses of NSSI and SBD. A clinical adolescent sample (N = 111, f/m = 73/38, age range = 12-19 years) was recruited from the inpatient units of three departments of child and adolescent psychiatry in Germany. All participating patients were interviewed by using the SITBI-G, and DSM-5 criteria of NSSI and SBD were operationalized from the SITBI-G data. Additionally, participants were given the Self-Harm Behavior Questionnaire (SHBQ), and SITBI-G was retested in a subsample. The SITBI-G shows moderate to good test-retest reliability, a very good interrater reliability, and a good construct validity. The results demonstrate that diagnoses of NSSI and SBD can be established using the SITBI-G, achieving moderate to good test-retest reliabilities and very good to perfect interrater reliabilities. Overall, the good psychometric properties of SITBI-G are comparable to the original version of the interview. Therefore, SITBI-G seems to be highly appropriate to assess SITBs, including the new DSM-5 Section 3 diagnoses NSSI and SBD in research and clinical contexts.

The present article gives a selective overview of recent studies on the role of nonsuicidal self-injury (NSSI) and suicidal behavior in the context of borderline personality disorder (BPD). Previous research found self-harming behavior, particularly NSSI, to constitute an easily accessible marker in the early detection of individuals at risk of development of BPD. The review further summarizes studies that investigated inter-relations between BPD features and self-harming behavior over time. Mainly, affective instability has been shown to play a role in the maintenance of NSSI and the increased risk of suicidal behavior among individuals with BPD. Finally, results about the effectiveness of treatment programs on the reduction of self-harming behavior among individuals with BPD are presented.