Abstract
Transdiagnostic vulnerabilities are key to understanding comorbidity of psychological disorders. Repetitive negative thinking (RNT) is a well-documented transdiagnostic cognitive vulnerability, yet the brain systems that support it remain unclear. Research on the neural basis of RNT is limited by a reliance on 1) content-specific components (i.e., worry and rumination) in isolation, 2) impersonal prompts to induce RNT, and 3) comparisons between clinical patients with healthy controls, rather than a dimensional analysis across the spectrum of psychiatric functioning. To address this, we designed a paradigm that elicited idiographic worries and ruminations during an fMRI scan in 39 young adults with a range of trait RNT scores. Through a series of univariate and multivariate analyses, this dissertation characterized the neural representation of RNT by identifying patterns of activity across brain networks that overlap between worry and rumination. This RNT system involves regions of brain networks that support self referential processing, memory and simulation, salience detection and network switching, and cognitive control. The results from this study have far-reaching implications for clinical, affective, and neurosciences.