Depression and Inflammation in Women With Breast Cancer: Risk and Resilience Factors.

Objective: Diagnosis with breast cancer is a profound stressor associated with increases in depression and inflammation. However, considerable variability in these outcomes is currently unexplained. We examined risk and resilience factors that may influence depressive symptoms and inflammatory markers in recently diagnosed breast cancer patients, including lifetime stressor exposure and psychological and behavioral resources. We focused on modifiable resources-sleep, physical activity, and coping resources-that can be leveraged to enhance women's recovery.

Methods: Women with stage 0-IIIA breast cancer ( N = 180) were assessed before radiation, chemotherapy, or endocrine therapy. The Stress and Adversity Inventory (STRAIN) was administered to measure total count and severity of lifetime stressors. Blood samples assessed plasma protein markers of inflammation (TNF-α, IL-6, and CRP) that were combined into a composite score. Self-report questionnaires evaluated depressive symptoms, sleep, physical activity, social support, self-esteem, optimism, and mastery.

Results: Total lifetime stressor count (β = 0.30, p < .0001) and severity (β = 0.12, p < .0001) were positively associated with depressive symptoms. Total lifetime stressor count (β = 0.01, p = .04), but not severity (β = 0.001, p = .17), was associated with higher inflammation. Sleep quality, social support, optimism, and mastery buffered the negative effects of lifetime stressor severity on depressive symptoms; social support and optimism also buffered stressor count on depressive symptoms ( p < .04). None of the moderators influenced the stress-inflammation association (all p s > .20).

Conclusions: Lifetime stressor exposure is associated with inflammation and depression in breast cancer patients. Interventions enhancing sleep quality, social support, optimism, and mastery may help prevent depression in this vulnerable group.