Mixture Modeling of Nonsuicidal Self-Injury and Binge Eating: Behaviors and Motives

Nonsuicidal self-injury (NSSI) and binge eating frequently co-occur. These behaviors are often used to alleviate distress. Previous studies examining this co-occurrence have used a variable-centered approach. The current study used a person-centered approach (mixture modeling) to examine how individuals cluster in groups based on their past-month NSSI, past-month objective and subjective binge episodes (OBEs and SBEs, respectively), and endorsement of coping motives for NSSI and eating in two large samples of emerging adults. Validators included self-report measures of emotion regulation, impulsivity, and negative affect. In Study 1, additional validators included lifetime history of mental health treatment and suicide attempts. In Study 2, additional validators included child abuse history. In both Study 1 and Study 2, a three-class solution provided the most interpretable fit with classes characterized as (a) low psychopathology; (b) the presence of OBEs and NSSI, and endorsement of NSSI coping motives; and (c) the presence of SBEs and NSSI, and endorsement of high levels of NSSI coping motives. In both studies, eating motives were equivalent in Classes 2 and 3, but NSSI motives were most strongly endorsed by Class 3. In Study 1, Class 2 endorsed higher rates of lifetime suicide attempts than Class 3. In Study 2, both Class 2 and Class 3 endorsed higher rates of child abuse than Class 1, although they did not differ from each other. The class structure and validator analysis were consistent across samples and measures. Results suggest that binge eating and NSSI tend to cluster together in otherwise healthy emerging adults.