Reciprocal associations between basic psychological needs frustration with nonsuicidal self-injury and disordered eating in daily life
| dc.contributor.author | Robillard, Christina Lauren | |
| dc.contributor.supervisor | Turner, Brianna | |
| dc.date.accessioned | 2025-07-25T22:41:29Z | |
| dc.date.available | 2025-07-25T22:41:29Z | |
| dc.date.issued | 2025 | |
| dc.degree.department | Department of Psychology | |
| dc.degree.level | Doctor of Philosophy PhD | |
| dc.description.abstract | Nonsuicidal self-injury (NSSI) and disordered eating (DE) often co-occur, likely due in part to their shared function of alleviating emotional distress. Basic psychological needs theory expands on this idea by proposing that the distress underlying NSSI and DE arises from frustration of fundamental needs for autonomy, competence, and relatedness. However, limited research has tested this hypothesis, hindering our understanding of whether this theory can be meaningfully integrated into functional models. The current dissertation addressed this gap by using ecological momentary assessment (EMA) to examine the reciprocal, within-person associations between needs frustration, NSSI, and two forms of DE (i.e., binge eating and purging) among 53 young adults who engage in NSSI and/or DE (56.6% women, Mage = 21.85, SD = 3.08). Over 21 days, participants completed multiple daily smartphone surveys assessing needs frustration, NSSI, binge eating, and purging. Dynamic structural equation modeling examined the within-person, three-hour lagged associations between these variables. Results revealed high comorbidity between NSSI and DE, with most participants who engaged in NSSI also engaging in at least one form of DE, and vice versa. Autonomy, competence, and relatedness frustration predicted increased odds of subsequent NSSI, while engagement in NSSI predicted increased needs frustration. In contrast, autonomy frustration predicted lower odds of binge eating and purging, while engagement in binge eating and purging predicted decreased frustration of all three needs. Overall, these results suggest that although needs frustration is relevant to understanding the daily dynamics of NSSI and DE, these behaviours do not function to restore thwarted needs – at least not on a three-hour timescale. The opposing associations between autonomy frustration and NSSI versus DE also suggest behaviour-specific mechanisms, which may elucidate the conditions under which an individual engages in one type of self harm over the other. Future research should examine these associations by: 1) assessing them across varied timescales (e.g., minutes to days); 2) identifying whether negative affect mediates the link between needs frustration and NSSI/DE; and 3) exploring a wider variety of behaviours (e.g., substance misuse) to clarify how needs frustration fits into transdiagnostic models of self-harm. | |
| dc.description.embargo | 2026-07-23 | |
| dc.description.scholarlevel | Graduate | |
| dc.identifier.uri | https://hdl.handle.net/1828/22515 | |
| dc.language | English | eng |
| dc.language.iso | en | |
| dc.rights | Available to the World Wide Web | |
| dc.subject | nonsuicidal self-injury | |
| dc.subject | disordered eating | |
| dc.subject | basic psychological needs theory | |
| dc.subject | self-determination theory | |
| dc.subject | needs frustration | |
| dc.subject | ecological momentary assessment | |
| dc.subject | experience sampling methodology | |
| dc.subject | transdiagnostic | |
| dc.subject | eating disorder | |
| dc.title | Reciprocal associations between basic psychological needs frustration with nonsuicidal self-injury and disordered eating in daily life | |
| dc.type | Thesis |