The Influence of Sleep Disturbance and Cognitive Emotion Regulation Strategies on Depressive Symptoms in Breast Cancer Patients

Background and Objective Depression and insomnia are highly prevalent and important distressing symptoms in breast cancer patients. And also, strategies to assist with cognitive emotions are important to help them cope with the stress of the disease. This study aimed to investigate the effects of sleep disturbance and these coping strategies on depressive symptoms in breast cancer patients. Methods We retrospectively reviewed the medical records of 119 breast cancer patients. Psychiatric assessments were done using Patient Health Questionnaire-9 (PHQ-9), Insomnia Severity Index (ISI), state subcategory of State and Trait Anxiety Inventory (STAI-S), Cancer-related Dysfunctional Beliefs about Sleep (C-DBS), Fear of Progression (FoP), and Cognitive Emotion Regulation Questionnaire (CERQ). Results Significant differences in the ISI, C-DBS, FoP, and in the regulation strategies of CERQ, were observed between depressed (PHQ-9 ≥ 10, n = 60) and non-depressed patient groups (PHQ-9 < 10, n = 59, p < 0.05). The PHQ-9 score correlated with the ISI, C-DBS, and FoP scores. All maladaptive strategies except blaming others were positively, and most adaptive strategies other than a refocus on planning were negatively correlated with PHQ-9 score (p < 0.01). Linear regression analysis revealed that breast cancer patient depression was predicted by high ISI score, high FoP score, and lower acceptance and higher catastrophizing item scores. Conclusions Cancer patient depression is associated with insomnia and the cognitive emotion regulation strategies used during their care. Discussions with these patients regarding coping strategies and sleep better will help to improve depressive symptoms.