Nonsuicidal Self-Injury (NSSI), or the deliberate damage of bodily tissue without suicidal intent, is a prevalent issue in young people. Relative to those who have never self-injured, young people with either recent (i.e., past-year) or distal (i.e., lifetime, but not in the past year) histories of NSSI demonstrate difficulties with emotion regulation, the process of modulating emotional responses. Emotion regulation difficulties are a risk factor for other forms of Self-Damaging Behaviours (SDBs), including binge drinking, substance use, and binge eating, which are more prevalent among individuals with a history of NSSI. Prominent theoretical models of NSSI and other SDBs posit that these behaviours may share a common function of altering negative mood states, explaining their frequent co-occurrence. The present study hypothesized that first-year university students with distal, recent, or no history of NSSI a) would differ in their rates of SDB engagement over seven months, and b) would differ in their strength of association between changes in stress and concurrent SDB engagement. Further, the present study hypothesized that emotional dysregulation would moderate the association between stress and SDB engagement. Multilevel modelling with longitudinal data from two cohorts of first-year undergraduates (N=540) revealed that students with either distal or recent NSSI histories were more likely to engage in substance use than their peers who had never self-injured, but did not report a greater frequency of binge eating or binge drinking. Regardless of NSSI history, substance use was unrelated to within-person changes in stress or emotional dysregulation. Higher-than-usual stress was associated with increased frequency of binge eating and binge drinking, but this association was unrelated to NSSI history or emotional dysregulation. Results suggest that elevated risk for substance use may persist even after NSSI has stopped, while other forms of SDBs (i.e., binge drinking and binge eating) were not predicted by NSSI history. Further, results suggest that some SDBs (i.e., binge drinking and binge eating) are enacted more frequently during periods of stress, but that this pattern is not unique to those with a history of NSSI or those who struggle to regulate their emotions. Consistent with person-centred models of NSSI recovery, these results suggest that vulnerability to some SDBs may persist even after NSSI has stopped. Future research should further examine the mechanisms underlying the complex association between NSSI and SDBs. / Graduate