Abstract

The Interpersonal Theory of Suicide posits that unmet interpersonal needs of thwarted belongingness and perceived burdensomeness are associated with the onset and severity of suicidal ideation. Research to date has largely examined the between-person associations of unmet interpersonal needs with suicide risk. Still, unmet interpersonal needs have been shown to vary significantly over time among adult clinical populations, yet little is known about the daily predictors and emotional impacts of this variability among adolescents at lower and higher risk for suicidal ideation. This dissertation sought to examine the day-to-day variability in unmet interpersonal needs and explore the risk factors for, and emotional consequences of, within-person fluctuations in unmet interpersonal needs among a sample of fifty-five adolescents with and without major depressive disorder (MDD), considered at higher- and lower-risk for suicidal ideation, respectively. The first study examined the day-to-day variability in unmet interpersonal needs and between- and within-person associations with emotional pain. The results of this study demonstrated that adolescents at higher risk for suicidal ideation had greater frequency, severity, and variability in unmet interpersonal needs. Nonetheless, adolescents at lower and higher risk for suicidal ideation both reported greater emotional pain on days when they reported greater perceptions of unmet interpersonal needs than usual for them. The second study sought to examine whether respiratory sinus arrhythmia (RSA), a physiological index of emotion regulation in social situations, moderated the within-person fluctuations in unmet interpersonal needs in response to negative social interactions. Results from this study demonstrated that participants reported more unmet interpersonal needs on days when they reported more negative social interactions. Among higher-risk adolescents, higher RSA was associated with less daily burdensomeness compared to their counterparts with lower RSA, especially on days with fewer negative social interactions. Taken together, these studies demonstrated that adolescents at lower and higher risk for suicidal ideation exhibit similar risk factors for and emotional outcomes of within-person fluctuations in unmet interpersonal needs. Thus, the longitudinal processes via which risk for unmet interpersonal needs and suicidal ideation is accrued across these two groups may be a matter of degree rather than kind.