Does Anger Expression Mediate the Relationship Between Parental Rejection and Direct and Indirect Forms of Non-suicidal Self-injury?

Non-suicidal self-injury (NSSI) is defined as the intentional destruction of one’s own body without an intent to die (e.g., self-cutting). On the other hand, indirect forms of self-injury refer to behaviors in which people harm themselves in an indirect way (e.g., substance use). Existing literature suggests that a negative parent–child relationship may increase vulnerability to NSSI and indirect forms of self-injury. However, little is known about the potential mediators that intervene in the aforementioned relationship. Therefore, the present work tests a path model to investigate whether the manner of anger expression—anger-in (redirect anger inwardly) or anger-out (express anger outwardly)—mediates the association between parental rejection and direct (specifically self-cutting) and indirect (specifically substance use) forms of self-injury in a cross-sectional sample of Italian adolescents. We assessed self-injury, parental acceptance/rejection, and the expression of anger using self-report questionnaires in 2464 high school students, aged 13–20 years (Mage = 15.93, SD = 1.49). Additionally, characteristics of NSSI were also assessed using semi-structured interviews. We found that parental rejection was significantly positively associated with both self-cutting and substance use. The aforementioned relationship was mediated through anger-in for self-cutting, and through anger-out for substance use. The current work demonstrated that anger expression might work as a bridge between invalidating caregiving environment (i.e., rejecting), in which an individual feels unloved and uncared for, and the occurrence of self-cutting and substance use. The salient role of anger management in the development of prevention and intervention programs for NSSI and indirect self-injury among adolescents is discussed.