THE EFFECTS OF RUMINATION AND WORRY ON CONTRAST AVOIDANCE IN MAJOR DEPRESSIVE DISORDER AND GENERALIZED ANXIETY DISORDER: AN APPLICATION OF CONTRAST AVOIDANCE MODEL OF WORRY

Open Access
Author:
Kim, Hanjoo
Graduate Program:
Psychology
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
September 16, 2016
Committee Members:
  • Michelle G. Newman, Thesis Advisor
  • Ginger Moore, Committee Member
  • Reginald B. Admans, Jr., Committee Member
Keywords:
  • rumination
  • worry
  • contrast avoidance
  • heart rate variability
  • major depressive disorder
  • generalized anxiety disorder
  • negative perseveration
Abstract:
Recent theories have suggested that both rumination and worry may facilitate emotional contrast avoidance in major depressive disorder (MDD) and generalized anxiety disorder (GAD). However, rumination and worry have never been compared in this regard. Therefore, this study aims to compare worry and rumination within the framework of the contrast avoidance model. Participants were selected based on GAD-Q-IV and BDI-II. Participants with high MDD, high GAD and low MDD & GAD controls were randomly assigned to engage in either rumination, worry or relaxation. In each condition, all participants were exposed to three emotion-inducing video clips designed to arouse sadness, fear and amusement. During the process, subjective emotionality and heart rate variability was measured. Results from multilevel modeling showed that rumination induction attenuated a sudden increase of sadness during sad follow-up video exposure. Similar to findings from a previous study, worry induction also attenuated abrupt increase of fear during the fear video exposure. However, such specificity was not found in amusement in response to amusement video exposure. Analysis of the group-by-induction condition interaction showed that the GAD group reported worry as more helpful in coping during the negative video exposure than the control group. However, rumination was linked to greater coping with sadness, regardless of group differences. Heart rate variability analysis revealed that worry was more closely related to cardiac defensive reactivity than rumination. RSA score in rumination was inconsistent across different trials. Nonetheless, compared to the control group, the GAD group reported the greatest comfort with sustained negative emotion, suggesting a greater tendency toward contrast avoidance. In addition, results showed that the reactivity of rumination and worry was nuanced by the type of stressor. In this study, rumination showed more reactivity to sadness, and worry was more reactive to fear. These results indicate that there is convergence and divergence of rumination and worry. Although rumination and worry share a similar emotion processing mechanism, results of this study show that presentation of their emotional response can vary based on the type of emotions. Based on these results, we discuss clinical implications and limitations of this study.