Objectives: This study examined the relationship between pain and mental health outcomes of depression and affect among survivors of breast cancer. The mediating role of physical activity was also tested.
Methods: Survivors of breast cancer (N=145) completed self-report measures of pain symptoms at baseline, wore an accelerometer for 7 days, and reported levels of depression symptoms and negative and positive affect 3 months later. Hierarchical linear regression analyses, controlling for personal and cancer-related demographics, were used to test the association between pain symptoms and each mental health outcome, as well as the mediation effect of physical activity.
Results: Pain positively predicted depression symptoms [F(6,139)=4.31, P<0.01, R2=0.15] and negative affect [F(5,140)=4.17, P<0.01, R2=0.13], and negatively predicted positive affect [F(6,139)=2.12, P=0.03, R2=0.08]. Physical activity was a significant (P<0.01) partial mediator of the relationship between pain and depression and between pain and positive affect.
Discussion: Participation in physical activity is one pathway through which pain influences mental health. Efforts are needed to help survivors of breast cancer manage pain symptoms and increase their level of physical activity to help improve mental health.
*Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
†Institute of Membrane and Systems Biology, University of Leeds, Leeds, UK
Supported by the Canadian Institutes of Health Research and the Canadian Breast Cancer Research Alliance, Canada, awarded to the first author. The authors declare no conflict of interest.
Reprints: Catherine M. Sabiston, PhD, Department of Kinesiology and Physical Education, McGill University, 475 Pine Avenue West, Montreal, Quebec, H2J 3J6 (e-mail: firstname.lastname@example.org).
Received August 27, 2011
Accepted September 17, 2011