Assessment of the association between non-suicidal self-injury disorder and suicidal behaviour disorder in females with conduct disorder

Abstract Background Non-suicidal self-injury (NSSI) and aggression have been demonstrated to serve as risk factors of suicidal behaviours (SB). Non-suicidal self-injury disorder (NSSID) and Suicidal Behaviour Disorder (SBD) are among new diagnostic categories for further studies in the DSM-5 classification. Methods We recruited 196 girls (aged 15.5 ± 1.2 years) diagnosed with conduct disorder (CD). All of them were assessed with respect of non-suicidal self-injury acts, suicidal attempts, psychopathology, self-esteem and general functioning. Results Age of NSSI onset was significantly lower compared to age of first suicidal attempt. SBD was present in 50.0% of patients with NSSID and the prevalence of NSSID in individuals with SBD was estimated at 52.2%. A diagnosis of NSSID, with at least 8 days of engagement in self-injuries during the preceding year, significantly predicted the risk of SBD. This effect appeared to be independent of depressive symptomatology. Limitations Our results cannot be generalized over the whole population of individuals diagnosed with CD because of a lack of male patients, as well as individuals with the most severe and mildest forms of CD. Causal inferences cannot be established due to a cross-sectional study design. Conclusions The NSSID with at least 8 days of engagement in self-injuries during the preceding year serves as a predictor of SBD independently of the effects of depressive symptoms. Longitudinal studies are required to confirm our findings.