Towards an effective and feasible treatment intervention for adolescents who present to hospital with nonsuicidal self-injury

The base rate of adolescent nonsuicidal self-injury (NSSI) is estimated to be between 40-61% in clinical samples. The high rate of psychiatric comorbidity and the increasing complexity of hospital presentations amongst these adolescents creates excess demands on limited hospital resources with associated implications for safety, clinical care and service costs. This makes NSSI a significant public health issue as well as a clinical service priority. Despite its acknowledged clinical and economic relevance, there are no empirically supported treatments for NSSI in adolescents and limited attention has been given to clinical feasibility for tertiary healthcare settings who shoulder most of the service provision. Providing effective and viable interventions that are clinically and developmentally relevant is therefore a legitimate and important focus of clinical research to reduce general hospital and psychiatric service demands and improve the functioning and mental health of young people with NSSI and their families. These considerations provided the justification for this research and shaped the focus of the studies that make up this thesis. Study one aimed to provide a critical review of the current treatment literature and found that there are currently no evidence-based interventions that target adolescents with NSSI that have been shown to be more effective than treatment as usual. Study two compared a clinical group of adolescents with NSSI to an age and gender matched non-clinical control group to gain a better understanding of leading theoretical models and their potential relevance to adolescent populations. The findings suggest that adult theories that prioritise the emotion-regulatory function of NSSI have application to adolescents and are therefore a useful basis from which to draw for adolescent models. The actual dimension of emotion regulation that is potentially important to adolescent-specific theory and treatment is highlighted. Based on these findings, study three details the development of a brief and feasible group treatment for adolescents who present to hospital with NSSI, the effectiveness of which is tested in a randomised controlled trial (RCT) in study four. The results of study four showed a significant improvement in the treatment versus control group on NSSI frequency and type, as well as on a number of core constructs of emotion regulatory theory, including, emotion regulation, emotional avoidance, depression and stress. No significant difference was found in terms of anxiety or family functioning. Importantly, the treatment group maintained their gains at 3-months post treatment and needed significantly fewer acute care contacts in this period.