The Impact of Depression on Adherence to Diabetes Self-Management Behaviors in Breast Cancer Survivors

Objective:Breast cancer survivors (BCS) have higher rates of depression which is associated with lower adherence to medications, diet, and physical activity. Managing diabetes (DM) requires adherence to several of these self-management behaviors (SMB), and BCS have an increased risk of DM. We investigated whether depressive symptoms were associated with adherence to DM SMB in a cohort of BCS. Methods: BCS with DM were surveyed semiannually for 2 years. Depression was assessed with the Hospital Anxiety and Depression Scale (HADS). Adherence to DM medication, diet, and physical activity was self-reported using the Medication Adherence Report Scale (MARS), Summary of Diabetes Self-Care Activities Assessment (SDSCA), and International Physical Activity Questionnaire (IPAQ), respectively. Using generalized linear equation modeling, the association of depressive symptoms with nonadherence to SMB was assessed, adjusting for age, race, marital status, education level, and beliefs about cancer and DM risk. Results: Among 244 BCS with DM, those who were nonadherent to medication, diet, and/or physical activity had higher depression scores (p < 0.01). In adjusted analyses, higher depression scores were independently associated with dietary (OR = 1.16, p < 0.001) and physical activity nonadherence (OR = 1.18, p < 0.001) but not with medication nonadherence. Concerns about medications was independently associated with medication nonadherence (OR = 1.17, p = 0.024). Conclusions: Higher depression scores are associated with nonadherence to DM SMB in this cohort of BCS. These findings highlight the importance of addressing depressive symptoms in BCS to help improve adherence to DM medications, diet, and physical activity.