Publication Date

2016-08-01

Availability

Open access

Embargo Period

2016-08-01

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Psychology (Arts and Sciences)

Date of Defense

2015-08-26

First Committee Member

Michael H. Antoni

Second Committee Member

Gail H. Ironson

Third Committee Member

Kiara Timpano

Fourth Committee Member

Armando Mendez

Fifth Committee Member

Sara Czaja

Abstract

The perceived impact of chronic fatigue on daily living (i.e., fatigue interference) is particularly relevant for patients diagnosed with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME), a medically unexplained illness associated with neuroendocrine and immune abnormalities. Literature suggests that fatigue interference is higher among women with CFS/ME than with other women facing chronic fatigue concerns, such as cancer survivors. To date, these comparisons have been primarily qualitative, limiting the ability to statistically control for related factors such as fatigue severity. Furthermore, greater fatigue interference in CFS/ME may relate to a suppressed cortisol awakening response (CAR) and heightened levels of the pro-inflammatory cytokine interleukin-6 (IL-6), though these associations have not been tested before. Finally, previous cognitive behavioral interventions including cognitive behavioral stress management (CBSM) have been shown to be helpful for this population, leading to improvements in psychological functioning and less dysregulated physiology. Given the high degree of fatigue and debilitating symptoms in CFS/ME, the efficacy of a 10 session, telephone-delivered CBSM intervention on fatigue interference and neuroimmune function over time was investigated. In Study 1, previously collected data on fatigue interference and fatigue severity were examined among 95 women with CFS/ME and 67 fatigued breast cancer survivors approximately 5 years post treatment. Analyses controlled for age, race/ethnicity, education level, marital status, employment status, number of children, time since diagnosis, and fatigue severity. Women with CFS/ME were found to endorse higher fatigue interference scores, p < .001. Next, neuroimmune correlates to fatigue interference scores were assessed among the CFS/ME sample. Again controlling for relevant covariates, higher fatigue interference scores were associated with a more diminished CAR with respect to increase (CARi), p = .02. No relationships were observed between fatigue interference and the CAR with respect to ground (CARg) or IL-6 levels. Additionally, these relationships were not amplified in the presence of high depressed mood. In Study 2, the effects of a 10-session, telephone-delivered cognitive behavioral stress management (CBSM) intervention on these variables were assessed. Participants included 93 women with CFS/ME from Study 1 who were randomized to either the CBSM (n = 53) or attention-matched control condition (n = 40). Results failed to identify intervention effects on changes in these variables from baseline (BL) to five months (5M) or nine months (9M) later. This may have been due to comparisons with a strong control condition, or to potential limitations in participants’ engagement via telephone. Interestingly, the CARi, CARg, post-awakening cortisol, and IL-6 were observed to decrease significantly over time in both conditions (ps < .05). Mechanisms of change might include gains in self-efficacy due to mastery of skills in either CBSM or attention control conditions. Examination of potential lagged effects of CBSM on cortisol and IL-6 levels warrants future investigation, as lowest levels of these biomarkers were at 9M. Future studies could also use videophone delivery of CBSM, which might bolster participant engagement in sessions and help to reach homebound or highly symptomatic CFS/ME patients. Emerging biomarkers of neuroimmune dysfunction in this population may yield insights into mechanisms underlying this elusive illness and help to identify new targets for psychosocial approaches to care.

Keywords

fatigue; CBSM; stress; chronic fatigue syndrome; immune; cortisol

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