Association of cancer caregiver stress and negative attribution style with depressive symptoms and cortisol: a cross-sectional study

PURPOSE: We examined the effect of informal cancer caregiver stress and negative attribution style (NAS) on depressive symptoms and salivary cortisol. METHOD: The sample came from a hospital bone marrow unit and caregiver support organizations and included 60 informal cancer caregivers (51.7% partners) of individuals with cancer (provided care for a median of 27.5 h per week for 12 months) and 46 non-caregiver participants. In this cross-sectional study, participants completed questionnaires assessing NAS and depressive symptoms and provided saliva samples to measure cortisol. RESULTS: Linear regressions demonstrated that cancer caregiver stress (p = 0.001) and the cancer caregiver stress by NAS interaction (p = 0.017), but not NAS alone (p = 0.152), predicted depressive symptoms. Caregivers independent of their NAS and non-caregivers high in NAS reported high depression while non-caregivers low in NAS reported low depression. Neither cancer caregiver stress (p = 0.920) nor NAS alone (p = 0.114), but their interaction, predicted cortisol (p = 0.036). Higher NAS was associated with a higher cortisol in both groups while non-caregivers had higher cortisol than caregivers. CONCLUSIONS: If the findings can be replicated, consideration of NAS in existing interventions to support informal cancer caregivers in managing chronic stress appears warranted.