UNIVERSITY of CALGARY the Influence of Rumination, Distraction
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UNIVERSITY OF CALGARY The Influence of Rumination, Distraction and Mindfulness on Cardiovascular Recovery from Stress by Brenda Louise Key A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF PSYCHOLOGY CALGARY, ALBERTA SEPTEMBER, 2010 © Brenda Louise Key 2010 Library and Archives Bibliothèque et Canada Archives Canada Published Heritage Direction du Branch Patrimoine de l’édition 395 Wellington Street 395, rue Wellington Ottawa ON K1A 0N4 Ottawa ON K1A 0N4 Canada Canada Your file Votre référence ISBN: 978-0-494-69488-6 Our file Notre référence ISBN:978-0-494-69488-6 NOTICE: AVIS: The author has granted a non- L’auteur a accordé une licence non exclusive exclusive license allowing Library and permettant à la Bibliothèque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par télécommunication ou par l’Internet, prêter, telecommunication or on the Internet, distribuer et vendre des thèses partout dans le loan, distribute and sell theses monde, à des fins commerciales ou autres, sur worldwide, for commercial or non- support microforme, papier, électronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. 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Abstract The central aims of the present study were to determine if mindfulness and distraction inductions would decrease rumination following a stressor and to investigate whether changes in post stressor rumination would influence cardiovascular recovery. Additional goals were to assess the influence of a brief mindfulness meditation intervention on rumination, mindfulness, depressed mood and symptoms of stress. Cardiovascular and psychological data was collected from 101 undergraduate students during two identical laboratory-testing sessions 5 weeks apart. Each testing session included a 5-minute baseline period, 5-minute stress task and a 15-minute recovery period. Participants were randomized to one of three conditions: mindfulness, distraction or control. During the recovery period, participants in the distraction condition received a distraction induction, those in the control condition received no induction and those in the mindfulness condition received a mindfulness induction. Participants in the mindfulness condition also received a 4-week mindfulness meditation intervention during the period between laboratory testing sessions while participants in the distraction and control conditions received no intervention. Results indicated that, at testing session two, participants in the mindfulness condition showed the greatest decreases in post stressor state rumination compared to the other conditions. The conditions did not differ on cardiovascular reactivity or recovery at either testing session. Mindfulness participants reported increases in trait mindfulness and decreases in depressed mood, following the brief mindfulness meditation intervention, compared to participants who did not receive the intervention. The brief mindfulness intervention was not associated with changes in ii trait rumination or symptoms of stress. The preliminary findings of the present study suggest the efficacy of a brief mindfulness meditation intervention for decreasing depressed mood, decreasing state rumination, in response to mental stress, and increasing mindfulness compared to a no-intervention control. iii Acknowledgements I would first like to extend my sincere thanks to my supervisor, Dr. Tavis Campbell, for his encouragement, guidance, and support throughout the completion of this dissertation. Your knowledge and enthusiasm for research and supervision have helped to make my graduate school experience a positive one. I would also like to thank my dissertation committee members, for their time and efforts in reviewing my dissertation. I wish to express my sincerest appreciation for the support of my classmates, who were there to encourage me through the struggles and celebrate the successes. Finally, I would like to express my heartfelt gratitude to my husband, Mark, and to my parents, Barb and Gord, for their unwavering love and support throughout my journey toward becoming a clinical psychologist. Words cannot express how much I have appreciated your wholehearted encouragement of my pursuits in psychology – this dissertation is dedicated to you. This research would not have been possible without financial support from the Social Sciences and Humanities Research Council (SSHRC), a Ralph Steinhauer Award of Distinction (Alberta Advanced Education) and the University of Calgary. This funding is gratefully acknowledged. iv Table of Contents Abstract……....................................................................................................................... ii Acknowledgements............................................................................................................ iv Table of Contents.................................................................................................................v List of Tables ................................................................................................................... viii List of Figures.................................................................................................................... ix List of Abbreviations ...........................................................................................................x INTRODUCTION ...............................................................................................................1 Cardiovascular Responses to Stress...........................................................................1 Cardiovascular Reactivity..................................................................................1 Cardiovascular Recovery...................................................................................3 Mechanisms Linking Cardiovascular Responses & Hypertension....................4 Rumination.................................................................................................................8 Theories of Rumination, Emotion & Arousal..........................................................11 Response Styles Theory of Rumination..........................................................12 Associative Network Theory ..........................................................................13 Two Factor Theory of Emotion ......................................................................13 Rumination Arousal Model.............................................................................14 Rumination & Cardiovascular Recovery.................................................................15 Interventions to Decrease Rumination.....................................................................18 Distraction......................................................................................................18 Mindfulness....................................................................................................19 Mechanisms of Mindfulness..........................................................................20 Research on Mindfulness & Rumination.......................................................22 Mindfulness versus Distraction as an Intervention for Rumination ..............23 Use of Distraction, Rumination & Mindfulness to Influence Affect.............26 Mindfulness & Cardiovascular Functioning..................................................28 Goals of the Present Study.......................................................................................31 Hypotheses...............................................................................................................31 v METHOD…… ..................................................................................................................34 Procedures................................................................................................................34 Randomization & Study Design .....................................................................34 Laboratory Testing Session.............................................................................35 Mindfulness Intervention................................................................................37 Measures ..................................................................................................................39 Data Analysis...........................................................................................................44