6 - (IOP41) Trajectories of Change in Affect Before and After Engaging in Non-suicidal Self-injury and Disordered Eating Behaviors

Affect, characterized by discrete emotions and positive (i.e., excitement and happiness) and negative (i.e., distress and sadness) emotional states, is a known risk factor for self-injurious behaviors (SIBs; including non-suicidal self-injury (NSSI) and eating disorder (ED) behaviors). Prior studies demonstrate increased negative affect and decreased positive affect predict engagement in SIBs. While theoretical models suggest SIBs may serve to regulate negative affect, findings on the specific affective changes surrounding SIBs remain mixed—particularly the role of positive affect. Additionally, affect is often examined as broad latent constructs, despite evidence that distinct emotions within these categories may have differential relationships with SIBs. The current study examines 1) the trajectories of the latent variables positive and negative affect pre- and post-SIB and 2) the trajectories of change in specific affective states. Adults (N = 124) who reported engaging in at least three SIBs in the past month completed six surveys a day assessing engagement in SIBs and ten affective states (i.e., positive affect: alert, determined, enthusiastic, excited, inspired; negative affect: afraid, distressed, nervous, scared, upset) for 14 days (6600 observations). Pre- and post-SIB trajectories of positive affect and negative affect were modeled using mixed-effects polynomial regression, centered on the observation at which the SIB was reported. There were significant, positive linear (B = 0.034) and quadratic (B = 0.002) trajectories of negative affect pre-SIB and a significant negative linear trajectory of negative affect post-SIB (B = -0.049). There was no significant effect of positive affect pre- or post-SIB, however, there was a significant linear decrease in alertness post-SIB (B = -0.062). Consistent with affect-regulation models of SIBs, negative affect significantly increased before SIBs and decreased afterwards, suggesting that individuals may engage in these behaviors to modulate aversive emotions. Similarly, a decrease in alertness post-SIB suggests that individuals experience a sense of numbness and reduced awareness of their bodily sensations Together, these findings suggest that affect, and potentially even bodily awareness, changes drastically in the hours leading up to a SIB and in the hours following a SIB. Thus, future interventions should provide emotion regulation strategies to target the reduction of negative affect and increase interoceptive awareness.