Modeling the dynamics of perceived burdensomeness, thwarted belongingness, and suicidal ideation in continuous time.

The interpersonal theory of suicide posits that perceived burdensomeness (PB) and thwarted belongingness (TB) are central to suicidal ideation (SI), where either one is sufficient for passive SI but both required for active SI. This study used continuous-time modeling to examine the relationship between PB, TB, and both passive and active SI. Three independent samples ( = 141) of participants with recent suicidal thoughts and behaviors completed 3-15 surveys per day for 28-30 days; each survey assessed PB, TB, passive SI, and active SI. Continuous-time residual dynamic structural equation models estimated auto- and cross-drift effects (instantaneous rates of change) between PB, TB, and their interaction on passive and active SI. Negative drift rates indicate resistance to shifts away from equilibrium. Both passive and active SI had negative auto-drift effects. There were significant negative cross-drift effects of PB, TB, and their interaction on both active and passive SI. The effects of PB, TB, and their interaction lasted 5-5.5 and 4.5-5 hr on passive SI and active SI, respectively. Auto-drift effects were significantly larger than cross-drift effects, which did not differ from each other. Both passive and active SI reduce their own rates of change, resisting shifts away from their equilibrium. Contrary to the interpersonal theory of suicide, these findings suggest that rather than precipitating SI, PB, TB, and their interaction resist shifts away from a person's typical levels of passive and active SI. (PsycInfo Database Record (c) 2025 APA, all rights reserved).