Neurocognitive functioning in adolescents with non-suicidal self-injury

Background:Non-suicidal self-injury (NSSI) is a highly prevalent transdiagnostic psychiatric symptom in adolescents. Research in adults has begun to investigate neurocognitive processes associated with NSSI as potential underlying phenotypes. However, research on neurocognitive function in adolescent patients with NSSI is scarce. Methods:In this study, we examined neurocognitive functioning in the domains of processing speed, attention, learning, working memory, and executive function in a relatively large sample of n = 240 adolescent patients engaging in NSSI and n = 49 healthy controls. Further, associations between neurocognitive performance and clinical characteristics in the patient group were examined. Results:While conventional regression analyses showed somewhat weaker neurocognition in the NSSI group in several domains, propensity score matching for IQ showed little evidence that patients engaging in NSSI showed worse neurocognition when general intelligence was considered. Further, a random forest machine learning algorithm was not able to classify NSSI vs. control groups based on neurocognitive features. Within the patient group, linear regression and latent class analyses yielded little evidence that neurocognitive performance was related with clinical characteristics or phenotypes. Limitations:As the study did not include a clinical control group, findings might not be specific to NSSI. Conclusions:Our findings challenge the importance of specific neurocognitive measures related to the presence or severity of NSSI in adolescents. Future studies should consider general intelligence as an important confounding factor and should focus on domains of affective cognition. Finally, longitudinal studies are needed to determine whether low neurocognitive performance serves to inform prognosis of NSSI or psychopathology in general.