Depression and Sleep Quality among Iranian Women with Breast Cancer

BACKGROUND AND PURPOSE: Breast cancer causes many psychological disorders such as sleep disturbances and depression. The current study was, therefore, intended to describe sleep quality and depression and to identify the association between these two psychological disorders among Iranian women with breast cancer. MATERIALS AND METHODS: This descriptive, analytical, cross-sectional study was carried out on 120 women with non-metastatic unilateral breast cancer undergoing chemotherapy in an outpatient chemotherapy unit of a major public hospital. A total of 120 women who had already undergone mastectomy procedure were selected via convenience sampling method. Data were collected by the Beck Depression Inventory-II (BDI-II) and the Pittsburgh Sleep Quality Index (PSQI). RESULTS: The mean score on BDI-II was 13.40 (± 6.51), and 30% (n=36) of women had mild depression and 14.2% (n=17) reported moderate-to-severe depression. The mean global score of sleep quality was found to be 6.48 (± 2.62). Furthermore, 50.8% (n=61) of women obtained a global PSQI score of 5. A positive correlation was found between depression scores and sleep quality scores (p=0.001, r= 0.48). Depression was also correlated with age, number of children, household gross income, sleep duration, sleep latency, and type of mastectomy procedure (p<0.05). Moreover, subjective sleep quality was correlated with number of chemotherapy sessions (p=0.001, r=-0.67) and daytime dysfunction (p=0.001, r=0.78). A positive correlation was also observed between sleep disturbances and habitual sleep efficiency (p = 0.02, r = 0.65). CONCLUSION: In conclusion, 30% of women had mild depression and 14.2% reported moderate-to-severe depression. The mean global score of sleep quality was found to be 6.48 (± 2.62), suggesting poor sleep quality. Furthermore, over half of the participants (50.8%) obtained a global PSQI score of 5 or greater which is indicative of poor sleep quality. A positive moderate correlation was also observed between depression and poor sleep quality.