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Publication Date

2009-10-14

Availability

UM campus only

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Psychology (Arts and Sciences)

Date of Defense

2008-05-27

First Committee Member

Michael H. Antoni - Committee Chair

Second Committee Member

Charles S. Carver - Committee Member

Third Committee Member

Frank J. Penedo - Committee Member

Fourth Committee Member

Michael E. McCullough - Committee Member

Fifth Committee Member

Suzanne C. Lechner - Outside Committee Member

Abstract

Prior work has provided support that women with breast cancer are hyper-responsive to stressful challenges and that Cognitive-Behavioral Stress Management (CBSM) interventions can lead to reductions in cortisol, a measure of physiological stress. It may follow that breast cancer patients would show decreases in cortisol levels if they are taught stress management techniques. The purpose of this study was to investigate post-intervention psychosocial processes (i.e., participants' perceptions of achieved specific skills targeted by CBSM and non-specific changes associated with the group experience) that may explain intervention-related changes in cortisol among a sample of women as they moved through medical treatment for non-metastatic breast cancer. It was hypothesized that (a) women receiving a 10-week, group-based stress management intervention during ongoing medical treatment for breast cancer would show reductions in late afternoon serum cortisol levels and (b) perceived ability to implement stress management skills or other experiences gained in the supportive group environment may explain changes in cortisol. Participants (N = 128) were women recruited 4-8 weeks post-surgery for non-metastatic breast cancer. Women were randomly assigned to receive either the 10-week CBSM intervention (N = 63) or a one-day psychoeducational seminar (n = 65). The intervention aimed to teach relaxation, cognitive restructuring, and interpersonal skills. Participants were assessed at study entry, 6 month follow-up (i.e., 3 months post-intervention) and 12 month follow-up (i.e., 6 months post-intervention). Latent Growth Curve Modeling (LGM) was used to test for differential effects of study condition on change over time in cortisol and the effects of specific and non-specific group processes on change in cortisol. Results indicated there was a significant effect of study condition on change over time in cortisol, relaxation skills, and assertiveness skills. There were not significant relationships between changes in cortisol and any of the components analyzed and mediation was not established using LGM. There was, however, a significant association between changes in an item that assessed cognitive restructuring and cortisol. Exploratory analyses of lagged (Time 2 controlling for Time 1) psychosocial processes mediating (Time 3 controlling for Time 2) cortisol changes were then conducted. Results indicated that condition's effect on cortisol approached significance and condition had a significant effect on the muscle relaxation component and cognitive restructuring item. Furthermore, there was evidence that intervention-related changes in confidence about using muscle relaxation and cognitive restructuring may help explain decreases in cortisol levels among this sample of women. Overall, this study demonstrated that a 10-week, CBSM intervention was associated with decreased cortisol levels and increased relaxation and assertiveness skills. Furthermore, there was a strong relationship between changes in cognitive restructuring and cortisol. Future research should investigate how changes in cortisol may be related to health behaviors and health outcomes among breast cancer patients.

Keywords

Group Therapy; Cognitive Behavioral Therapy; Relaxation Training

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