The German version of the self-injurious thoughts and behaviors interview (SITBI-G): a tool to assess non-suicidal self-injury and suicidal behavior disorder

Background: 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. Methods: 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. Results: 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. Conclusions: 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.