UNIVERSITY OF CALGARY

UNIVERSITY OF CALGARY
A Pilot Trial of Light Therapy on Fatigue, Mood, Sleep Quality, and Quality of Life in
Individuals with Post-Treatment Cancer-Related Fatigue
by
Jillian Angela Johnson
A THESIS
SUBMITTED TO THE FACULTY OF GRADUATE STUDIES
IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE
DEPARTMENT OF PSYCHOLOGY
CALGARY, ALBERTA
SEPTEMBER, 2013
© Jillian Angela Johnson 2013

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Abstract
Cancer-related fatigue (CRF) is a common and distressing symptom reported by
individuals with cancer, with 33% of patients continuing to experience fatigue for months or
years following treatment. Despite its prevalence, CRF remains relatively undertreated and
poorly understood. Light therapy is an effective treatment for a variety of fatigue disorders. This
study evaluated the impact of a one-month light therapy treatment on fatigue, mood, sleep
quality, and quality of life (QOL) in post-treatment cancer survivors with CRF. Eight
participants were randomized to either bright white light (BWL) or dim red light (DRL) and
completed baseline and post-treatment measures. Participants in both the BWL and DRL
treatments groups showed reductions in fatigue, and improvements in sleep quality and QOL.
Given the small sample size and the time of year the study was conducted, the results should be
interpreted with caution.

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Acknowledgements
First and foremost, I would like to thank my supervisor, Dr. Tavis Campbell, for his
guidance and mentorship over the past 5 years. Without his constant encouragement and support,
I would not be on the path I am on today. I would like to thank Dr. Linda Carlson and her lab
members in the Department of Psychosocial Resources for their unwavering support and
guidance. I would also like to express profound gratitude to Dr. Sheila Garland for all of her hard
work and dedication in designing this project and ensuring its success.
Thank you to my committee members, Dr. Mike Antle and Dr. Bejoy Thomas, for their
feedback and their participation in the oral examination. I would like to express my appreciation
for Dr. Tak Fung and his assistance with the data analysis, as well as my fellow colleagues in the
Behavioural Medicine Laboratory for all of their support and feedback. Thank you to all of the
Tom Baker Cancer Centre staff and community support programs that helped with recruitment
efforts, and all of the participants that volunteered their time to take part in the study. Finally, I
would like to thank my husband and my family for providing me with the resources and
emotional support required to continue on this journey. This project is funded by the Canadian
Cancer Society, Alberta Innovates-Health Solutions, and the Canadian Institutes of Health
Research.

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Table of Contents
Abstract....................................................................................................................................
Acknowledgements..................................................................................................................
List of Tables...........................................................................................................................
List of Figures..........................................................................................................................
List of Symbols and Abbreviations…………..........................................................................
Introduction..............................................................................................................................
Impact on Functioning.................................................................................................
Quality of Life…………………………………….…….…………………...
Mood……………………………………………….…….………………….
Mechanisms of CRF…………….………………………….…….……...…………..
Peripheral Fatigue………………………….………….…….……………….
Central Fatigue……………………………….……….…….………………..
Models of CRF………………………………….…….……….……………..
Treatments for CRF……………...……………………….….………….……...……
Education and Counseling………………………….….…………….………
Non-Pharmacological Interventions……………….….….………………….
Pharmacological Interventions……………………..….…………………….
Light Therapy……………..………….........................................................................
Circadian Rhythm Entrainment…………………...…………………………
Improvements in Mood…………………………..………………………….
Rationale for Current Study….……………………….….……..…………...............
Aims……………………………………………………..…………………………..
Primary Aim……………………………………………..…………………..
Secondary Aim………………………………………..……………………..
Hypotheses…………………………………………………..………………………
Primary Hypothesis………………………………...………………………...
Secondary Hypothesis…………………………..…………………………...
Method.....................................................................................................................................
Trial Design.................................................................................................................
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Participants...................................................................................................................
Recruitment and Screening…………………………………….………….………...
Equipment………...……………………………………………….….……………..
Measures…………………….…………...…………………………..……………...
Screening Tools………………………………………..…………………….
Medical History and Demographics…………………..…………………….
Primary Outcome Measure…………………………...……………………...
Secondary Outcome Measures…………………………………..…………..
Intervention..................................................................................................................
Sample Size Calculation……………………………………………...……………...
Data Analysis………….…………………………………………….…..….………..
Results………………………………………………..............................................................
Recruitment and Sample Characteristics…………………………...………………..
Treatment Adherence...................................................................................................
Adverse Effects………………………………………................................................
Primary Outcome Measure…………………………………………………………..
Fatigue………..……………………………....................................................
Secondary Outcome Measures…………………………………………….................
Mood Disturbance……………………………………....................................
Insomnia Symptom Severity………………………………………................
Sleep Quality....................................................................................................
Quality of Life…………………..……………………………..……………..
Sleep Log………………………………………………...….…….................
Credibility and Expectancy…………………………………………..……...
Discussion................................................................................................................................
Strengths………………………………………….………………………………….
Limitations……………………………………………………………...……………
Future Research……………………………………..…………...…………..………
Conclusion…………………………………………………………………...………
References................................................................................................................................
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