Are anticholinergic medications used for overactive bladder associated with new onset depression? A population-based matched cohort study

Purpose — Prior research has suggested that anticholinergic medications used for overactive bladder are associated with depression. Our objective was to test this hypothesis by comparing rates of new onset depression among anticholinergic medication users and those who were prescribed an alternative class of overactive bladder medication.

Methods — We used administrative data records from the province of Ontario, Canada and a matched cohort design. We matched patients who were newly prescribed an oral anticholinergic to those prescribed a beta-3 agonist medication in a 2:1 ratio which included a propensity score that included 75 baseline characteristics. The primary outcome of depression was measured using a validated definition, and the at-risk period for our outcome of interest was between the initial date the prescription was filled, and up to 3 months after the end of continuous usage of that medication. Hazard ratios were estimated using Cox proportional hazards regression.

Results — We matched 23,622 beta-3 agonist users (mirabegron) to 47,324 anticholinergic users (most commonly tolterodine, oxybutynin and solifenacin). The rate of depression was similar among beta-3 agonist users (10.64 per 1000 patient-years) and anticholinergic users (11.99 per 1000 patient-years). In our primary analysis, the risk of depression among anticholinergic users was not significantly different compared to beta-3 agonist users (hazard ratio [HR] 1.08 (95% CI 0.92-1.28, p=0.35)).

Conclusion — Contrary to a previous report, overactive bladder anticholinergic medications do not appear to be associated with new onset depression.