Applying the Tripartite Model to the Link between Non-Suicidal Self-Injury and Suicidal Risk

Abstract

Objectives: The current study applies and expands the Tripartite Model of Anxiety and Depression to elaborate the link between non-suicidal self-injury (NSSI) and suicidal behavior. We propose a structural model of NSSI and suicidal risk, in which negative affect (NA) predicts both anxiety and depression, low positive affect (PA) predicts depression only, anxiety is linked to NSSI, and depression is linked to suicidal risk. Method: Four hundreds and eighty seven undergraduates participated. Data were collected by administering self-report questionnaires including the Positive and Negative Affect Schedule, the Deliberate Self-Harm Inventory, the Scale of Suicidal Risk, and the Symptom Checklist-90-R. We performed hierarchical regression and structural equation modeling to test the proposed structural model. Results: The results largely support the proposed structural model, with one exception: anxiety was strongly associated with NSSI and to a lesser extent with suicidal risk. The conclusions of this study are as follows: The co-occurrence of NSSI and suicidal risk is due to NA and anxiety, and suicidal risk can be differentiated by the presence depression and low PA. That is, in this model, there are two pathways. First, NA predicts anxiety and depression, and predicts NSSI and suicidal risk through the mediation of anxiety. NA also predicts suicidal risk through the mediation of depression. Second, low PA predicts depression and also predicts suicidal risk through the mediation of depression. Further theoretical and practical implications are discussed.