Date of Award

Spring 6-6-2018

Document Type


Degree Name

Doctor of Philosophy in Clinical Psychology (PhD)


Clinical Psychology

First Advisor/Committee Member

Amy Mezulis, PhD

Second Advisor/Committee Member

Jacob Bentley, PhD

Third Advisor/Committee Member

Bonnie McGregor, PhD


Somatic symptoms are a significant medical and mental health concern that affects healthy adults and places a significant burden on healthcare systems. The perseverative cognition hypothesis posits that perseverative cognition results in prolonged physiological activation that may be interpreted as somatic symptoms. The purpose of this study was to further examine this hypothesis in a sample of young adults. First, I hypothesized that perseverative cognition would prospectively predict somatic symptoms after controlling for anxiety and depression. Second, I hypothesized that parasympathetic nervous system functioning, measured as respiratory sinus arrhythmia (RSA) and sympathetic nervous system functioning, measured as electrodermal responding (EDR) would mediate this relationship. RSA and EDR were measured before, during, and after a stressor task to provide measures of basal levels, reactivity to the stressor, and recovery from the stressor respectively.

These hypotheses were tested in a sample of 220 young adults. Participants ranged from 18 to 39 years old (M = 19.63, SD = 12.10), 84.5% of the participants were female, and 65.5% were Caucasian. Perseverative cognition predicted somatic symptoms in the unexpected direction in both hypothesized models (RSA: β = -0.23, p = 0.001; EDR: β = -0.23, p = 0.074). When anxiety and depression were removed as covariates, somatic symptoms were significantly predicted by perseverative cognition in the expected direction in both models (RSA: β = 0.38, p < 0.001; EDR: β = 0.37, p = 0.003). Neither RSA nor EDR at any time point were significantly related to either perseverative cognition or somatic symptoms, and no indirect effects were observed. Individual mediations revealed that RSA recovery significantly predicted somatic symptoms (β = 0.16; p = 0.029) such that individuals whose parasympathetic nervous system re-engaged following the stressor experienced a higher level of somatic symptoms. Additionally, individuals who reported higher levels of perseverative cognition experienced greater increases in EDR during the stressor task (β = 0.17; p = 0.041). Overall, the findings of this study suggest that perseverative cognition is related to sympathetic nervous system functioning, while parasympathetic nervous system functioning is related to reporting of somatic symptoms. Future research directions and clinical implications are discussed.