Clinical specificity of acute versus chronic self-injury: measurement and evaluation of repetitive non-suicidal self-injury.

Overall, previous studies on the prevalence of non-suicidal self-injury (NSSI) behaviors in the general population have stressed the importance of differentiating between occasional and repetitive NSSI, examining different severity levels (e.g., frequency and variety of methods), as well as investigating the diverse psychopathological correlates of NSSI. However, existing NSSI measures have not been explicitly developed by to comply with the NSSI diagnostic criteria proposed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The purpose of this study is to develop a measure of repetitive NSSI by considering its essential features, as described in the proposed DSM-5 as well as in other clinically relevant aspects emerging from case reports. Two independent samples of participants (N1=383 young adults and 251 adolescents; N2=953 adolescents) belonging to the general population were involved in the present study. The questionnaire showed satisfactory fit statistics and reliably discriminated between occasional and repetitive self-injurers (Area Under Curve, AUC=0.755). The pattern of correlations with psychopathological measures confirmed a more clinically-compromised profile for repetitive rather than occasional self-injurers.