Tracking Anger at Self and Others and Non-Suicidal Self-Injury Cognitions and Behavior: An Ecological Momentary Assessment Study in Emerging Adults

Although anger is theorized to play a key role in the manifestation of non-suicidal self-injury (NSSI), prospective research in real-world settings is limited. Therefore, the present study examines (1) whether individuals with and without a history of NSSI differ in anger levels in their natural setting and (2) whether heightened self- or other-directed anger predicts NSSI cognitions (i.e., thoughts and self-efficacy to resist NSSI) and behavior in daily life. Using ecological momentary assessment in 60 emerging adults (ages 18–22) with and without past-year NSSI, participants completed eight daily surveys over 12 days, yielding 4,587 assessments (median compliance=83.3%; IQR=71.9–91.7). Emerging adults with past-year NSSI reported higher anger at self and others than peers without NSSI. Among those who self-injured, higher-than-usual anger at self, but not at others, predicted greater NSSI thought intensity and lower self-efficacy to resist NSSI 90 minutes later. Anger at self also predicted NSSI behavior, but this association became non-significant when controlling for NSSI thoughts. These findings highlight differences in the object of anger between individuals with and without past-year NSSI and underscore the clinical importance of interventions focused on improving emotion regulation and reducing self-directed anger to decrease NSSI thoughts and prevent self-injury.