Date of Award

Winter 12-2019

Author's School

Graduate School of Arts and Sciences

Author's Department

Psychology

Degree Name

Master of Arts (AM/MA)

Degree Type

Thesis

Abstract

Elevated neuroticism (N) potentiates the depressogenic effects of stressful life events (SLEs). We first replicate this association using longitudinal data (N=971 older adults) from the St. Louis Personality and Aging Network (SPAN) study. Here, SLEs prospectively predicted future depressive symptoms, especially among those reporting elevated N, even after accounting for prior depressive symptoms and previous SLE exposure (NxSLE interaction: p=0.016, ΔR2=0.003). These findings were further replicated in cross-sectional analyses of the Duke Neurogenetics Study (DNS), a young adult college sample with neuroimaging data (n=1,343: NxSLE interaction: p=0.019, ΔR2=0.003). Because evidence suggests that stress may promote depression by inducing reward-related neural dysfunction, we next tested whether neuroticism moderates the association between SLEs and reward-related ventral striatum (VS) activity in the DNS (N=1,195). Here, neuroticism moderated the association between SLEs and reward-related left VS activity such that individuals with high neuroticism who were also exposed to more SLEs had blunted left reward-related VS activation (NxSLE: p=0.017, ΔR2=0.0048), which was associated with a lifetime depression diagnosis (r=-0.07, p=0.02). These data suggest that neuroticism may promote vulnerability to stress-related depression, and that sensitivity to stress-related VS dysfunction is a potential neural mechanism underlying this effect.

Language

English (en)

Chair and Committee

Dr. Ryan Bogdan

Committee Members

Dr. Thomas Oltmanns, Dr. Renee Thompson

Comments

Permanent URL: https://doi.org/10.7936/88ch-e044

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