['Depressive symptoms are commonly experienced by cancer patients, especially those with advanced disease. The link between depression and survival outcome in cancer patients has received increasing attention. The purpose of this study was to determine, after adjusting the known covariates, whether the depressive symptoms during the first cycle of chemotherapy can predict the mortality of patients with advanced non-small cell lung cancer (NSCLC).', 'Patients with stage III or IV NSCLC were recruited from a large teaching hospital located in northern Taiwan. Depressive symptoms were assessed during the first cycle of chemotherapy using the Hospital Anxiety and Depression Scale-Depression subscale. A cut-off of 7/8 was used to categorize patients into depressed and non-depressed groups. All patients were followed up until the end of the study. The follow-up time ranged from 10 to 30 months.', 'The study sample consisted of 90 NSCLC patients. Twenty patients (22.2%) were categorized as depressed. The median survival time in the depressed group was significantly shorter than that of the non-depressed group (11.83 vs. 24.47 months, P\u2009=\u20090.017). After controlling for demographic and clinical factors, depressive symptoms remained significantly (p\u2009=\u20090.023) associated with a shorter survival time. Compared to the non-depressed group, the depressed group had twice the risk of death (HR\u2009=\u20092.18, 95% CI\u2009=\u20091.11 to 4.28).'] Do depressive symptoms during the first chemotherapy cycle predict mortality in patients with advanced non-small cell lung cancer?