Rumination and affective outcomes in women diagnosed with breast cancer

Breast cancer entails a series of physical, psychosocial and existential challenges that extend into the survivorship period through late side effects from treatment and the potential for disease recurrence. Consequently, higher levels of depressive and anxious symptoms are experienced along the disease trajectory, although positive change, termed post-traumatic growth, can coexist. Perseverative thinking, specifically rumination, has been linked to the development and maintenance of depression and anxiety in clinically-well populations as well as to post-traumatic growth in the cancer context. With limited research into the pathways by which rumination might exert this dual influence, the overall aim was to increase understanding of how subcomponents of rumination are differentially related to positive and negative psychological outcomes in women diagnosed with breast cancer. Given the complexity of the rumination construct, the absence of a specific measure for the context of illness required the development of the Multidimensional Rumination in Illness Scale (MRIS) as an initial step to achieving this aim. Studies 1 and 2 addressed the development, pilot testing, refinement and validation of the MRIS, with solid psychometric properties being demonstrated. A cross-sectional study of individuals with breast cancer (Study 3) found that brooding rumination was associated with depressive and anxious symptoms whereas both instrumental and intrusive rumination were associated with post-traumatic growth. As timing of rumination can be significant, the longitudinal approach in Study 4 revealed more distinctly how patterns of rumination differentially affect psychological outcomes along the illness trajectory. These findings provide a basis for the enhancement of psychological interventions to minimise distress and optimise post-traumatic growth. While cognitive-behavioural therapy (CBT) approaches have been successful in managing distress, CBT does not specifically address rumination, placing importance on the evaluation of the effectiveness of newer CBT modalities, such as Mindfulness-Based Cognitive Therapy, that target rumination through the addition of disclosure techniques and mindfulness meditation.