Suicide attempts during adolescence: Testing the system dynamics of the interpersonal theory of suicide

Abstract Introduction Despite increased efforts to prevent suicide, attempts to die by suicide are rising amongst youth in the United States. Testing causal theories that depict suicide attempts from an adolescent development perspective could bolster prevention and intervention efforts. This study using system dynamics modeling to appraise whether a prevalent theory of suicide, the Interpersonal Theory of Suicide, predicts suicide attempts across adolescence. Methods A system dynamics computational simulation model was conceptualized based on the Interpersonal Theory of Suicide, as described by Joiner and Van Orden et al. This model was parameterized with representative longitudinal data on adolescents in the United States who attempted suicide across four waves from the National Longitudinal Survey of Adolescent and Adult Health. Results Though able to predict exponential growth in suicide attempts for early adolescents, the Interpersonal Theory of Suicide, when specified as a dynamic theory, did not adequately predict the nonlinear changes in suicide attempts from adolescence into adulthood. The theory was amended with potential feedback loops from literature and tested for fit. Conclusions The study builds on a field of emerging views that suicide dynamics should be tested to account for nonlinear feedback effects. Results suggest that the Interpersonal Theory of Suicide should be amended to include the effect of interventions after an attempt and the dynamic developmental processes during adolescence that affect suicide behaviors over time.