Assessing the Functions of Non-suicidal Self-injury: Psychometric Properties of the Inventory of Statements About Self-injury (ISAS)

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.