The present study reports the psychometric properties of the Inventory of Statements About Self-injury (ISAS), a measure designed to comprehensively assess the functions of non-suicidal self-injury (NSSI). The ISAS assesses 13 functions of NSSI, as well as the frequency of 12 NSSI behaviors. The ISAS was administered to 235 young adults from a college population who had performed at least one NSSI behavior. Consistent with previous research, ISAS functions comprised two factors representing interpersonal and intrapersonal functions. In addition, the ISAS factors exhibited excellent internal consistency and expected correlations with both clinical constructs (e.g., borderline personality disorder, suicidality, depression, anxiety) and contextual variables (e.g., tendency to self-injure alone). Findings support the reliability and validity of the ISAS. The ISAS may be useful in research and treatment contexts as a comprehensive measure of NSSI functions.

Theoretical and empirical literature suggests that nonsuicidal self-injury (NSSI) may represent a particularly important risk factor for suicide. The present study examined the associations of NSSI and established suicide risk factors to attempted suicide in four samples: adolescent psychiatric patients (n = 139), adolescent high school students (n = 426), university undergraduates (n = 1,364), and a random-digit dialing sample of United States adults (n = 438). All samples were administered measures of NSSI, suicide ideation, and suicide attempts; the first three samples were also administered measures of depression, anxiety, impulsivity, and borderline personality disorder (BPD). In all four samples, NSSI exhibited a robust relationship to attempted suicide (median Phi = .36). Only suicide ideation exhibited a stronger relationship to attempted suicide (median Phi = .47), whereas associations were smaller for BPD (median rpb = .29), depression (median rpb = .24), anxiety (median rpb = .16), and impulsivity (median rpb = .11). When these known suicide risk factors and NSSI were simultaneously entered into logistic regression analyses, only NSSI and suicide ideation maintained significant associations with attempted suicide. Results suggest that NSSI is an especially important risk factor for suicide. Findings are interpreted in the context of Joiner's interpersonal-psychological theory of suicide; specifically, NSSI may be a uniquely important risk factor for suicide because its presence is associated with both increased desire and capability for suicide.

There is much work to be done to better understand suicidal thoughts and behaviors among youth. We strongly encourage future research to: (1) continue improving the conceptualization and operationalization of suicidal thoughts and behaviors; (2) improve etiological understanding by focusing on individual (preferably malleable) mechanisms; (3) improve etiological understanding also by integrating findings across multiple units of analyses and developing short-term prediction models; (4) demonstrate greater developmental sensitivity overall; and (5) account for diverse high-risk populations via sampling and reporting of sample characteristics. These serve as initial steps to improve the scientific approach, knowledge base, and ultimately prevention of suicidal thoughts and behaviors among youth.

Impulsivity has been proposed as an important construct in nonsuicidal self-injury (NSSI). Yet, research on the relationship of impulsivity to NSSI has been mixed. The present study clarified this relationship using a multifaceted measure of impulsivity (i.e., UPPS Impulsive Behavior Scale), and a computer-based behavioral measure of inhibitory control (i.e., a stop-signal task). Participants were 82 confirmed self-injurers and 86 controls recruited from a college population. Self-injurers and controls performed similarly on the stop-signal task. On the UPPS, self-injurers were best distinguished by Urgency (committing rash decisions when faced with negative emotions), and distinguished to a lesser degree by lack of Premeditation (inability to delay action in order to plan) and Sensation Seeking (seeking excitement and adventure). Among self-injurers, lack of Perseverance (inability to stay with a task through completion) predicted more recent and frequent NSSI. Conceptual and clinical implications are discussed.

Objective Non-suicidal self-injury (NSSI) is a growing public health concern, especially among adolescents. In the current edition of the Diagnostic and Statistical Manual of Mental Disorders, NSSI is classified as a criterion of borderline personality disorder (BPD). However, a distinct NSSI disorder will now be included in DSM-5 as a “condition requiring further study.” Importantly, at this time, there is little direct evidence supporting the DSM-5 proposal over the DSM-IV classification. To address this need, the current study examined the extent to which NSSI occurs independently of BPD, and has clinical significance beyond a diagnosis of BPD in adolescent psychiatric patients. Method NSSI disorder was assessed based on the proposed DSM-5 criteria in 198 adolescents ages 12 to 18 (74% female; 64% Caucasian, 14% Hispanic, 10% African American, and 12% mixed/other ethnicity) from a psychiatric hospital. Major Axis I disorders, Axis II BPD, and suicide ideation and attempts were assessed with structured clinical interviews; emotion dysregulation and loneliness were measured with validated self-report questionnaires. Results First, results indicate that NSSI disorder occurs independently of BPD. Specifically, although there was overlap between the occurrence of BPD and NSSI disorder, this overlap was no greater than that between BPD and other Axis I disorders (e.g., anxiety and mood disorders). Second, NSSI disorder demonstrated unique associations with clinical impairment – indexed by suicide ideation and attempts, emotion dysregulation, and loneliness – over and above a BPD diagnosis. Conclusions Taken together, findings support the classification of NSSI as a distinct and clinically significant diagnostic entity.