Self-Injurious Thoughts and Behaviors Interview: Development, Reliability, and Validity in an Adolescent Sample Matthew K. Nock, Elizabeth B. Holmberg, Valerie I. Photos, and Bethany D. Michel Harvard University The authors developed the Self-Injurious Thoughts and Behaviors Interview (SITBI) and evaluated its psychometric properties. The SITBI is a structured interview that assesses the presence, frequency, and characteristics of a wide range of self-injurious thoughts and behaviors, including suicidal ideation, suicide plans, suicide gestures, suicide attempts, and nonsuicidal self-injury (NSSI). This initial study, based on the administration of the SITBI to 94 adolescents and young adults, suggested that the SITBI has strong interrater reliability (average = .99, r = 1.0) and test–retest reliability (average = .70, intraclass correlation coefficient = .44) over a 6-month period. Moreover, concurrent validity was demonstrated via strong correspondence between the SITBI and other measures of suicidal ideation (average = .54), suicide attempt (= .65), and NSSI (average = .87). The authors concluded that the SITBI uniformly and comprehensively assesses a wide range of self-injury-related constructs and provides a new instrument that can be administered with relative ease in both research and clinical settings. Keywords: suicide, self-injury, assessment, reliability, validity Although impressive advances have been made in the study of self-injurious thoughts and behaviors (SITB) over the past several decades (Hawton & van Heeringen, 2000; Jacobs, 1999; Maris, Berman, & Silverman, 2000), the rates of SITB in the general population have remained virtually unchanged (Kessler, Berglund, Borges, Nock, & Wang, 2005). This may be due in part to a lack of clarity and consistency in the way SITB are measured across research studies and clinical settings. Science and practice in this area will advance most rapidly with the availability of measures that clearly and consistently assess these behaviors. A review of all existing measures of self-injury-related con- structs is beyond the scope of this article; however, a brief over- view of prior work and a summary of key limitations will help to place the current work in context. Given the importance of SITB and the problems in the measurement of these constructs, the National Institute of Mental Health (NIMH) recently commis- sioned two systematic reviews of suicide assessment measures available for use with children/adolescents (Goldston, 2000) and adults/older adults (Brown, 2000). These comprehensive reviews identified numerous, valuable measures currently used to assess self-injury-related constructs; however, in doing so they also high- lighted several important limitations. One significant limitation is that many of the measures currently available do not use clear and specific definitions of the SITB being assessed. Although opera- tional definitions for distinct types of SITB have been outlined (O’Carroll, Berman, Maris, & Moscicki, 1996), many measures fail to adhere to these definitions, and many do not differentiate among different SITB constructs (e.g., some measures classify all self-injurious behaviors as “parasuicide” or “suicide attempts,” regardless of whether the individuals intended to die from their behavior). The use of broad and inconsistent definitions makes it difficult to compare results from different studies and also can obscure important differences in the data and lead to erroneous conclusions (see Linehan, 1997, for a review). For instance, a recent reanalysis of data from the National Comorbidity Survey (Kessler et al., 1994) revealed that requiring intent to die in the definition of a suicide attempt reduced the U.S. lifetime prevalence of self-reported suicide attempts from 4.6% to 2.7% and exposed important differences between those with intent to die and those who engaged in self-injury without such intent (Nock & Kessler, 2006). Yet most measures that include questions about suicide attempts do not specifically assess the presence of intent to die (Nock, Wedig, Janis, & Deliberto, in press). A related concern is that many of the measures used to assess SITB do not provide clear, objective data about the presence and frequency of the SITB in question, but instead provide data on somewhat arbitrary scales that may be difficult for clinicians and researchers to interpret (Blanton & Jaccard, 2006; Kazdin, 2006). For instance, the fact that a patient scored a “7” on a measure of the severity of suicidal ideation may be less readily useful to most clinicians than knowing that an individual has thought about killing herself daily for the past month or that she has made three suicide attempts in the past year. Data reported in nonarbitrary metrics such as the presence, frequency, and characteristics on different types of SITB, although basic, will likely be of value for clinical and research purposes. Matthew K. Nock, Elizabeth B. Holmberg, Valerie I. Photos, and Bethany D. Michel, Department of Psychology, Harvard University. This research was supported by grants from the Milton Fund and Talley Fund of Harvard University to Matthew K. Nock. We are grateful to the members of the Laboratory for Clinical and Developmental Research for their assistance with this work and to the adolescents and families who participated in this study. Correspondence concerning this article should be addressed to Matthew K. Nock, Department of Psychology, Harvard University, 33 Kirkland Street, Cambridge, MA 02138. E-mail: nock@wjh.harvard.edu Psychological Assessment Copyright 2007 by the American Psychological Association 2007, Vol. 19, No. 3, 309 –317 1040-3590/07/$12.00 DOI: 10.1037/1040-3590.19.3.309 309