Association between Regular Use of Analgesics before Cancer Diagnosis and Occurrence of Mood Disorders

We aimed to determine the relationship between the use of analgesics prescribed for pain management and the onset and progression of mood disorders using a large-scale cohort database. We calculated hazard ratios (HR) with 95% confidence intervals (CI) for patient risk of developing mood disorders based on age, income, health-related variables, disease history, Charlson comorbidity index, and analgesics prescription behavior (Models 1-3). Additionally, we determined the risk of mood disorder occurrence by age group (Model 4) using a proportional hazards regression model. The age- and income-adjusted HR (Model 1) was 1.8275. The age-, income-, BMI-, and physical-activity-adjusted HR (Model 2) was 1.882. The fully adjusted HR (Model 3) was 1.698. Compared with no analgesic use, nonregular use (HR = 1.386) and regular use (HR = 1.698) was associated with a higher risk of mood disorders. Among patients older than 50 years, those who participated in physical activity (less than five days) had a lower risk of mood disorders than those who did not. This suggests that it may be useful for preventing mood disorders in older cancer survivors. A high risk of comorbidities and regular use of analgesics are risk factors for developing mood disorders. Therefore, our results suggest that cancer survivors with a high risk of comorbidities and a history of regular analgesic use should undergo careful psychiatric consultation.