3 - (SYM 62) Exploring the Intersection Between Momentary and Developmental Dynamics in Non-suicidal Self-injury

Ecological momentary assessment (EMA) studies find that NSSI is maintained over time by relieving aversive emotions and generating desirable feelings (Brown et al., 2022). While there is extensive research on the affective contexts surrounding NSSI, less is known about whether these patterns of emotions shift across different phases of NSSI engagement. Complex dynamic systems approaches suggest that the factors leading to the emergence of psychopathology are in turn influenced by the presence of the condition (Selby et al., 2022). Accordingly, NSSI momentary dynamics (i.e., proximal affect) may differ depending on the length of behaviour engagement (i.e., developmental dynamics). The present study explores whether the affective dynamics of NSSI vary based on whether someone has recently started (i.e., onset phase) or has engaged in NSSI for a long time (i.e., maintenance phase).

195 young adults aged 17-30 (85.05% female, M_age = 22.31, SD = 3.20) completed an assessment of their NSSI history (e.g., age of onset; SITBI-R; Fox et al., 2020) followed by three weeks of EMA. EMA surveys assessed negative (NA) and positive affect (PA) (items from PANAS-X; Watson & Clark, 1994) and were delivered in the morning/evening and at four other points randomly throughout the day. We used multi-level modeling wherein time was centered on NSSI events and random intercepts were specified per participant. The model included linear and quadratic time predictors and their interaction with length of NSSI engagement. NA significantly increased following NSSI (Est. = 0.04, SE = 0.02, p = .037) and this relationship was not moderated by previous NSSI duration (p > .05). Exploratory analyses suggested that lifetime NSSI frequency was differentially associated with PA trajectories (Est. = -0.01, SE = 0.003, p = 0.01). Specifically, for those with a history of less frequent NSSI PA decreased before NSSI and increased after the behaviour whereas for those with repetitive NSSI PA continued to decline.

The authors will discuss how these findings might inform the delivery of ecological momentary interventions (EMIs) as the emotional shifts from NSSI underpin most treatments that heavily emphasize teaching people alternate emotion regulation and coping skills. Namely, EMIs could target different affective mechanisms based on the individual’s NSSI history. The presentation will outline key directions for future research. For example, since the functions of NSSI fluctuate within individuals (Coppersmith et al., 2021), subsequent studies could incorporate separate EMA periods.