The present study provided evidence for psychometric properties of the Inventory of Statements About Self-Injury in a sample of opioid and alcohol abusers in Iran. The results showed ISAS is a useful inventory for the Iranian population. Findings have noetic and conceptual implications for understanding the measurement of non-suicidal self-injury in opioid and alcohol abusers. the results show the frequency of NSSI and its functions are relatively stable over time. The behavior with the greatest stability was severe scratching. Burning, pinching, and pulling hair were three of the most common and clinically severe NSSI behaviors.
The results of the confirmatory factor analysis after the exploratory factor analysis showed the factor loadings of all sub-inventories were more than 0.6, indicating that the factor rotation caused an increase in the power of factor loadings sub-inventories. Cronbach’s alpha for the total score and both hidden factors were similar to the original version of the inventory in a study by Klonsky et al. (
5,
6), which was higher than 0.7, indicating this inventory had a good fit for the Iranian population of opioid and alcohol abusers.
The results of the study by Klonsky et al. have suggested separate categories (interpersonal and intrapersonal) for NSSI functions (
5,
6). However, some studies emphasize NSSI functions overlap and are interrelated (
18). According to a meta-analysis, intrapersonal functions are less common causes of NSSI compared to interpersonal functions such as emotional regulation, which is often difficult for substance abusers. Nevertheless, the above-mentioned study, as well as the current study, do not suggest that focus should only be on one function in an individual (
19). In factor analysis, “Self-care” and “peer-bonding” had the highest and lowest factor loadings, respectively. The theory of social learning supports these findings. Sometimes adolescents, by injuring themselves, reinforce self-care behavior, seek attention from their family, and gain social status among their peers.
Substance abuse is associated with suicidal tendencies. Non-lethal suicide attempts can be a risk factor for future suicide attempts and one of the main reasons for hospitalization in psychiatric wards (
20). This study examined self-cutting and slit wrestling, the most important types of self-injurious behaviors among drug abusers (
21,
22). Limited access to dangerous means of suicide may play an important role in reducing self-injury attempts in the studied sample. The most important groups at risk are youths, prisoners, and all those committed intentional self-injurious behaviors during their lifetime (
23).
Given the convergent and divergent validity, there is a positive and significant correlation between both distress tolerance and impulsivity with intentional self-injurious behaviors, consistent with previous studies. In addition, alcohol abuse and self-injurious behaviors are associated with low degrees of distress tolerance (
19). Distress tolerance, an individual difference variable, points to the capacity of experience and resistance to emotional distress. Distress tolerance has increasingly been seen as an important concept in development, a new insight into the onset and maintenance of mental health, as well as prevention and treatment of mental disorders. People with low distress tolerance engage in behavioral deviances such as drug abuse in an erroneous attempt to deal with their negative emotions and to relieve their psychological pain (
10). Impulsivity is also a key factor in the incidence of NSSI behaviors (
23). Addiction is a powerful predictor of the persistence of drug abuse, and understanding the relationships between these factors can help reduce the recurrence of drug abuse (
24).
Moreover, ISAS is the first inventory localized among opioid and alcohol abusers in Iran, which can safely and reliably examine NSSI behavior in this population. Therapists can now evaluate patients’ responses to the treatment and follow up on their progress over time. In addition to interview, therapists can use this instrument to create treatment plans. This tool can also be used to monitor treatment progress and reduction in self-injurious behaviors. Therefore, it is important to adequately train the staff to use this instrument.
A limitation of this study was respondents’ low educational level; the researcher resolved this limitation by personally reading all the questions for the participants. Also, the fact that very few study participants (1.06%) were females makes it difficult to generalize the results to the female population. In addition, this study only examined individuals, abusing opioids, and alcohol. Manifestations and related functions may be different in abusers of other substances and hence limits the generalizability of the findings. Future studies can examine self-injurious behaviors and the applicability of ISAS, as an instrument, in the female population as well as in abusers of substances other than opioids and alcohol.
The most important achievement of this study is that it provides thorough evidence based on data collected from a sample covering a variety of cultures and ethnicities from multiple regions of the country, including the north, south, east, west, and central parts of Iran. Therefore, this tool can be used as a representative measure of relevant behaviors in the Iranian population.
5.1. Conclusions
The Persian version of the Inventory of Statements About Self-Injury has high validity and reliability among the Iranian population of opioid and alcohol abusers. Further research is needed to investigate the causal relationship between clinical symptoms and suicidal ideation and decreased resilience.