Non-suicidal self-injury (NSSI) refers to any deliberate and direct destruction of body tissue in the absence of suicidal intention (1, 2). NSSI manifests in various behavioral patterns such as cutting or carving the skin, burning the skin, or deliberately fracturing one's bones (3) and is associated with psychiatric casenesses such as Borderline Personality Disorder (BPD), suicidality, anxiety, and depression (e.g., 4, 5–7). The prevalence of NSSI is common with symptoms endorsed in approximately 20–30% of adolescents in Turkey (8), Pakistan (9), Korea (3), Belgium (10), the USA (11), Germany (12), and Spain (13). Concerning the prevalence of NSSI in Iran, a lifetime prevalence of 12.3% without gender differences was reported among Iranian university students (14).
NSSI often presents during adolescence and is a significant mental health challenge affecting about 70% of children and adolescents with mental health problems (e.g., 15, 16–20). Across six geographical regions (Asia, Australia/New Zealand, Canada, Europe, United Kingdom, USA) over 19 years, Swannell et al. (2014) reported that the prevalence of NSSI was 17.2% for adolescents across different countries, schools, universities, and in community-based samples. Given the high prevalence of NSSI among adolescents (21, 22), assessing NSSI among this age group is of utmost importance.
The Inventory of Statements about Self-Injury (ISAS), developed by Klonsky et al. (4), assesses different NSSI functions. The ISAS consists of two parts. Part I assesses the frequency of 12 different types of NSSI behaviors, which were performed "intentionally and without suicidal intent," including banging/hitting, biting, burning, carving, cutting, wound picking, needle-sticking, pinching, hair pulling, rubbing skin against rough surfaces, severe scratching, and swallowing chemicals. Additionally, this part includes five further questions evaluating descriptive and contextual factors of NSSI, including the age of onset, the experience of pain during NSSI, whether NSSI is performed alone or around others, the time between the urge to self-injure and the act of NSSI, and if the person wants to end self-injuring or not. If participants confirm one or more NSSI behaviors, they are directed to complete Part II of the ISAS, which evaluates five intrapersonal and eight interpersonal NSSI functions (i.e., Affect Regulation, Anti-dissociation, Anti-suicide, Autonomy, Interpersonal boundaries, Interpersonal influence, Marking distress, Peer bonding, Self-care, Self-punishment, Revenge, Sensation seeking, and Toughness) through 39 items with three items for each function, rated on a 3‐point Likert type scale, ranging from 0 (not relevant) to 2 (very relevant). A higher score corresponds to a greater number of functions or motives for engaging in self-injury.
Given the importance of NSSI assessment, the ISAS has been translated and studied in various countries, including Sweden (23), Turkey (24), Australia (25), South Korea (3), Spain (26), Iran (27), Pakistan (9), and Norway (28). In the original study, Klonsky et al. (4) examined the psychometrics of ISAS with 235 college students in the USA who had performed at least one NSSI behavior. Results of exploratory factor analysis (EFA) with Promax rotation indicated a robust two-factor solution. The first factor represented eight interpersonal functions (Autonomy, Interpersonal boundaries, Interpersonal influence, Peer-bonding, Revenge, Self‐care, Sensation‐seeking, and Toughness), and the second factor represented five Intrapersonal functions (Affect regulation, Anti-dissociation, Anti-suicide, Marking distress, and Self‐punishment). The same factor structure was replicated in Turkey (24), Australia (25), South Korea (3), and Pakistan (9). Similarly, the two-factor model yielded good fit with the sample of eating disorder or cluster B personality disorder patients in Spain (26). In the most recent study with a sample of Norwegian students, the results confirmed the two-factor model of ISAS. The "Marking distress" function loaded on the interpersonal factor, which was originally loaded on the intrapersonal factor. The "self-care "function was also loaded on the intrapersonal factor, which originally belonged to the interpersonal factor (28). In Iran, Zarghami et al. (27) examined the psychometrics of the ISAS among adult opioid and alcohol abusers. The EFA revealed a single-factor solution, which yielded an adequate fit in the subsequent confirmatory factor analysis (CFA). While important, Zarghami et al. (27) correlated seven error covariances in their one-factor solution, which may not provide a clear interpretation of the true factor structure (29, 30).
Beyond a stable factor structure, other psychometric properties of the ISAS are positive. The internal consistency of ISAS' factors and the 13 functions were in the acceptable to excellent range in both community (3, 4, 24, 25, 28, 31) and clinical samples (9, 23, 26, 27). Additionally, in support of their convergent validity, ISAS scores were associated with related constructs such as borderline personality symptoms, suicidality, depression, anxiety, impulsivity, and contextual variables such as the tendency to self-injure alone, suicidal ideations, and decreased resilience (3, 4, 24, 25, 27, 28, 31); ISAS scores were also positively correlated with emotion dysregulation (26, 28) and negatively with distress tolerance (27).
While ISAS is a widely used measure to assess NSSI, its psychometrics have not been comprehensively examined in the Iranian youth sample, and thus, it is unclear if the findings from other cultures are generalizable to Iran. For instance, in Iran, the predominant religious traditions strongly prohibit suicidal behavior. Moreover, this practice is evident in schools, where adolescents are taught that a suicide attempt is among Islam's gravest sins, and if one commits suicide, he/she will be deprived of paradise and its merits. Therefore, it is likely that individuals may feel guilt once they attempt to commit suicide, and they may engage in NSSI instead of suicidal attempts. Thus, a separate study is needed to examine the ISAS in Iranian culture. Furthermore, while the prevalence of NSSI seems to be high and is becoming more common, especially among Iranian adolescents (32), NSSI is not a well-known and well-studied subject in Iran. Thus, this gap needs to be filled using valid NSSI measures. To this end, the current study investigated the factor structure, reliability, and validity of the ISAS with a sample of 655 Iranian school attending adolescents. We will test the proposed two-factor structure of the ISAS using the CFA. Then, the reliability of the ISAS will be estimated. Finally, the convergent validity of the ISAS scores will be examined by calculating the associations between ISAS scores and related variables, such as depression and anxiety (e.g., 24), suicidal ideation/ suicide attempts (e.g., 3), and emotion regulation (e.g., 26, 28).