Real-World Antidepressant Prescribing Patterns and Comparative Safety Outcomes of Commonly Prescribed Antidepressants in Patients with Depressive Disorder: A Multicenter OMOP-CDM Study.

Background/Objectives: Real-world antidepressant use for depressive disorder varies across clinical settings. This study aimed to characterize prescribing pathways and evaluate the comparative safety of frequently prescribed antidepressants in a large multicenter cohort with newly diagnosed depressive disorder. Methods: We conducted a retrospective multicenter observational study using electronic health record data standardized to the OMOP Common Data Model (1999-2026) in adults initiating antidepressants. Prescribing patterns among 13,381 patients were visualized using sunburst plots and Sankey diagrams. Comparative safety, escitalopram vs. sertraline and trazodone, was evaluated across 18 hospitals (n = 44,542) for nine clinical safety outcomes using propensity score-matched Cox proportional hazards models and empirically calibrated random-effects meta-analysis. Results: Selective serotonin reuptake inhibitors, particularly escitalopram (21.4%, n = 2868), were the preferred antidepressant. Common adjunctive medications included trazodone (14.6%, n = 794) and quetiapine (14.0%, n = 761), though utilization varied across hospitals. No clear differences were detected for most safety outcomes between cohorts. However, empirically calibrated QTc prolongation risk was significantly increased with sertraline relative to escitalopram (HR 1.75, 95% CI 1.10-2.78), a signal requiring further confirmation. Conclusions: This study demonstrates substantial institutional variation exists in real-world antidepressant treatment pathways and combination strategies. While comparative safety profiles were broadly comparable across evaluated outcomes, the isolated QTc prolongation signal for sertraline warrants targeted external confirmation. Furthermore, trazodone and escitalopram cohorts should not be regarded as clinically interchangeable first-line options, supporting individualized, evidence-based antidepressant selection in routine clinical practice.