Risk of major depressive disorder in adolescent and young adult cancer patients in Japan

OBJECTIVE: To estimate the risk of major depressive disorder (MDD) in adolescent and young adult (AYA) patients with cancer in Japan and identify risk factors for MDD among these patients. METHODS: This was a matched cohort study using a large claims database in Japan. Included patients were aged 15–39 years, newly diagnosed with cancer during 2012–2017 and assessable for a follow‐up period of 12 months. Kaplan–Meier estimates and Cox proportional hazards models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for MDD in the AYA patients with cancer versus age‐, sex‐ and working status‐matched cancer‐free controls. A subgroups analysis of the AYA patients with cancer was performed to explore MDD risk factors. RESULTS: A total of 3559 AYA patients with cancer and 35,590 matched controls were included in the analysis. Adolescent and young adult patients with cancer had a three‐fold higher risk for MDD compared with cancer‐free controls (HR, 3.12; 95% CI, 2.64–3.70). Among cancer categories with >100 patients, patients with multiple cancer categories, including those with metastatic cancer (HR, 6.73, 95% CI, 3.65–12.40) and leukemia (HR, 6.30; 95% CI, 3.75–10.58), had the greatest MDD risk versus matched controls. Patients who received inpatient chemotherapy as initial treatment had a higher risk for MDD than patients without chemotherapy (HR, 0.43; 95% CI, 0.30–0.62). CONCLUSIONS: Adolescent and young adult patients in Japan with cancer are at high risk for MDD. Particularly, those with multiple cancer categories, leukemia, and those who receive aggressive anticancer treatments should be monitored closely for symptoms of MDD.