Curtis, CateMorrison, Tobey2025-09-042025-09-042025https://hdl.handle.net/10289/17636Understanding why young people engage in self-injurious behaviours is crucial for improving their well-being outcomes. While Non-Suicidal Self-Injury (NSSI) has been explored to some extent in New Zealand, research on Outward-Directed Injurious Behaviour (ODI) remains limited both within New Zealand and internationally. Although traditionally considered distinct, emerging research suggests that NSSI and ODI may share more commonalities than previously recognised, particularly regarding their role in emotion regulation. This study used Ecological Momentary Assessment (EMA) to examine the functions and emotion antecedents of NSSI and ODI among 16–30-year-olds in New Zealand. Eleven participants provided EMA data, and seven of these also participated in interviews, offering deeper insights. Findings reveal key similarities between NSSI and ODI as coping mechanisms for managing distress. NSSI was primarily used to reduce anxiety, while ODI was used to alleviate frustration. 'Neutral' emotions were the most common precursor for NSSI, while 'anger' was the main trigger for ODI. Interview material revealed that participants often felt tired, overwhelmed, anxious, or bored when selecting 'neutral,' as these emotions weren't available as response options. Feelings of shame led to a shift from urges to engage in either behaviour to NSSI, while ODI was closely associated with anger in similar situations. Despite differences in how these behaviours are expressed, both serve to regulate negative emotions, highlighting the need to consider their shared functions in therapeutic and research contexts. This is especially important for ODI, which has traditionally been viewed as a delinquent behaviour, rather than as a coping strategy.enAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.ecological momentary assessmentnon-suicidal self-injurynssioutward-directed injurious behaviour (ODI)emotion regulation/copingmental healthyoung peopleThesis