Final Abstract for URS Program
Researchers have established that rumination is a debilitating symptom that positively correlates with symptoms of depression. Rumination involves self-focused attention, often negative, as a means of coping with a depressed mood or sadness. The Ruminative Responses Scale (RRS) is a tool used to measure rumination severity that includes two subsets of rumination: brooding and reflection. Brooding rumination is related to passive and judgmental thoughts about one’s circumstances and is therefore associated with higher levels of past and current depression. Although brooding is thought to be a maladaptive response to feelings of depression, past studies suggest that the reflection subtype may act in an adaptive way as it is a problem-solving mechanism and has shown to lead to a decrease in depression duration. The present study seeks to identify brain mechanisms associated with rumination and brooding subtypes to explore why some people exhibit one over the other. Specifically, this study will examine the blood-oxygen level dependent signal variability (BOLD-SV) patterns within brain regions thought to be associated with rumination subtypes in relation to depression, which has yet to be analyzed in the literature. A sample of 79 women were recruited to complete a resting-state fMRI scan, RRS, and a depression symptom measure. The first aim of this study was to identify BOLD-SV differences between regions of interest (ROIs) implicated in reflection and brooding, and we hypothesized that (1) reflection and brooding subtypes will show distinct correlations with BOLD-SV in neural ROIs implicated in rumination. The second aim of this study was to determine whether there are differences in BOLD-SV of the neural regions associated with reflection and brooding based on depression history. Consistent with this aim, we predicted that there would be (1) lower BOLD-SV in ROIs associated with brooding for the currently-depressed group and (2) higher BOLD-SV in ROIs associated with reflection for both the past depression and no depression group. In accordance with the first aim, this study found a significant effect of rumination subtype on BOLD-SV in the dlPFC, (F3,75 = 4.86, p = .005). Specifically, greater levels of brooding were associated with lower BOLD-SV in the dlPFC, (t(78) = -2.612, p = .01). In support of our first hypothesis under our second aim, significantly reduced BOLD-SV was found in the dlPFC for the currently-depressed group as compared with the no depression group (t(63) = -2.436, p = .018). This study discusses the implications of these results and suggests directions for future studies to strengthen the findings of this foundational research.