Depression is a major risk factor for the development of dementia in people with lower urinary tract symptoms: A nationwide population-based study

BACKGROUND/OBJECTIVES: Studies have shown a strong relationship between depression and dementia. Lower urinary tract symptoms (LUTS) were reported to be independently associated with depression and dementia. However, the relationship between depression and cognitive dysfunction in patients with LUTS is not well characterized. METHOD: We conducted a matched cohort study by using a one-million population-based dataset in Taiwan. A total of 15,944 patients with LUTS aged 50 or older were included from 2001 to 2005 and followed up until their death or the end of 2012. During the follow-up period, 1958 cases developed depression subsequently and were defined as the study group. 7832 patients without depression were then identified as control group, matching by age, gender, insurance premium, status of catastrophic illness certificate, and the index year in a 1:4 ratio. The primary outcome was the onset of dementia. LUTS, depression, dementia, and other comorbidities were defined by the International Classification of Disease, 9th Revision, Clinical Modification coding system. Cox hazards models and Aalen Johansen curves were applied to measure the influence of depression on the risk of dementia in patients with LUTS. RESULTS: The crude incidence of depression among people with LUTS was 12.3%. The incidence of dementia in the depression group was significantly higher than that in the control group (12.2% versus 8.9%; P < 0.001). Depression was associated with a significantly greater risk of subsequent dementia after adjusted for socioeconomic status, number of outpatient visits and multiple comorbidities (adjusted hazard ratio: 1.32; 95% confidence interval: 1.13–1.54). CONCLUSIONS: Depression is a major risk factor for the onset of subsequent dementia in patients with LUTS. Early screening and interventions for depression in patients with LUTS may be important to maintain cognitive function.