Background: In high income countries, cancer is one of the leading causes of death, with co-morbid depression contributing to the risk of increased mortality. However, both cancer and depression are neglected conditions in low income countries. The current study assessed the magnitude of depression and the association of pain complaints with depression among patients with cancer in a low income country.
Method: In this cross-sectional study participants were 390 patients with established diagnosis of cancer, who were recruited consecutively when visiting a tertiary treatment centre in Addis Ababa, Ethiopia. The occurrence of depression was determined using the nine items Patient Health Questionnaire (PHQ-9). Major depressive disorder was confirmed: (1) when five or more of the PHQ-9 symptoms were endorsed as occurring for at least 'more than seven days', with the exception of suicidal ideation item which counted as a positive rating if it had occurred even once in the previous fifteen days. (2) one of the symptoms has to be either depressed mood or loss of interest. Pain complaint was measured by Numeral Rating Scale (NRS) and severity of pain was assessed using Verbal Rating Scale (VRS).
Results: The prevalence of major depressive disorder was 16.4% (95%CI: 13.1%, 20.4%), and subthreshold depression was 17.4% (95%CI: 14.0%, 21.5%). Pain complaints occurred in 69.0% (95%CI: 64.3%, 73.4%) of the participants. The odds of having a major depressive symptom was over four times higher among participants who had pain.
Limitations: The study was cross sectional and liable to recall bias. Recruitment was carried out in a tertiary referral hospital, which might lead to the selection of more economically well-off and educated participants limiting generalizability of the study. Moreover, we did not control for cancer types, which may be related to pain and the experience of depression. Some of the somatic symptoms in PHQ9 may also be related to the cancer itself.
Conclusions: This study highlights the clinical significance of both depression and pain complaints in patients with cancer in a low income country. Exploration of the impact of depressive disorders on quality of life and outcome of cancer is an important area for further research in low income countries.