Objective Previous studies have shown that lung cancer patients experience depression before their diagnosis. However, the patient characteristics that are risk factors for depression before the diagnosis of lung cancer are unclear. We therefore performed this study to identify the characteristics that are risk factors for depression in lung cancer patients. Methods We performed a prospective observational study that included 183 patients who visited our department for suspected lung cancer between August 2014 and March 2017. These patients completed a Quick Inventory of Depressive Symptomatology-Self Report questionnaire. Ten patients with a history of depression were excluded. Results Among the remaining 173 patients, 110 were diagnosed with lung cancer. Among these 110 patients, 57 had depression. A poor performance status (PS) was significantly more prevalent in patients with depression than in those without. Furthermore, a multivariate analysis revealed that a poor PS was the only independent risk factor for depression before the diagnosis of lung cancer. Conclusion Physicians can use this information to evaluate whether patients have depression before the diagnosis of lung cancer.
Keywords: before diagnosis; depression; lung cancer; performance status; self-report questionnaire.