Self-Efficacy Buffers the Relationship Between Dementia Caregiving Stress and Circulating Concentrations of the Proinflammatory Cytokine Interleukin-6

Objective: The proinflammatory cytokine interleukin (IL)-6 has been linked with health morbidity, particularly risk for cardiovascular disease (CVD). The purpose of this study was to investigate the potential protective role of coping self-efficacy on the relationship between caregiving stress and circulating concentrations of IL-6. Methods: A total of 62 elderly caregivers of patients with Alzheimer's disease (mean age: 74 years) were assessed for plasma concentrations of IL-6, caregiving-related overload, and coping self-efficacy. Multiple regression was used to examine the main effects of stress and self-efficacy, as well as the interaction between stress and self-efficacy, in predicting plasma IL-6 after controlling for age, gender, resting blood pressure, and obesity. Results: There was a significant interaction between stress and self-efficacy in predicting IL-6. Post-hoc examination indicated that when self-efficacy was low, stress was significantly related to IL-6 (beta = 0.43). However, when self-efficacy was high, stress was not significantly related to IL-6 (beta = -0.10). Conclusion: Caregiving stress in combination with low coping self-efficacy is significantly related to IL-6, a known risk marker for health morbidity, particularly CVD. However, stress was not associated with IL-6 with high self-efficacy. Although limited and preliminary, these results point to a potential protective effect of self-efficacy on caregiver health that can be tested in longitudinal studies. (Am J Geriatr Psychiatry 2010; 19: 64-71)