Androgen deprivation therapy and depression in men with prostate cancer treated with definitive radiation therapy

Background There is no consensus on the association between the use of androgen deprivation therapy (ADT) and the risk of developing depression. This study investigated the association between ADT use and the development of depression, outpatient psychiatric services, inpatient psychiatric services, and suicide in a homogeneous group of men with prostate cancer (PC) treated with definitive radiation therapy (RT) after controlling for multiple sources of selection bias. Methods This was a retrospective, observational cohort study of 39,965 veterans with PC who were treated with definitive RT and were diagnosed by the US Department of Veterans Affairs health care system between January 1, 2001, and October 31, 2015. Exposure was ADT initiation within 1 year of the PC diagnosis. The primary outcome was new development of depression. Secondary outcomes were outpatient psychiatric use, inpatient psychiatric use, and suicide. Results During follow-up, 934 patients were newly diagnosed with depression, 7825 patients used outpatient psychiatric services, 358 patients used inpatient psychiatric services, and 54 patients committed suicide. In the multivariable competing risks regression model, ADT was associated with the development of depression (subdistribution hazard ratio [SHR], 1.50; 95% confidence interval [CI], 1.32-1.71; P < .001). ADT was also associated with outpatient psychiatric utilization (SHR, 1.21; 95% CI, 1.16-1.27; P < .001). Finally, ADT was not associated with inpatient psychiatric utilization or suicide. Conclusions An increase in the risk of depression and the use of outpatient psychiatric services was observed in a large cohort of men with PC who received ADT with definitive RT. These results may provide further evidence for the long-term risks of ADT for psychiatric health in the treatment of PC.