Reciprocal association between depression and peptic ulcers: Two longitudinal follow-up studies using a national sample cohort.

This study was aimed to explore the bidirectional association between depression and peptic ulcers. The ≥20-year-old participants of the Korean National Health Insurance Service-National Sample Cohort from 2002 to 2013 were included in the study. In study I, 30,306 depression patients were 1:4 matched with 121,224 control I participants. In study II, 127,590 peptic ulcer patients were 1:1 matched with 127,590 control II participants. The stratified Cox-proportional hazards models were used to analyse the hazard ratio (HR) of depression for peptic ulcers (study I) and of peptic ulcers for depression (study II). A total of 8.9% (2,703/ 30,306) of depression patients and 7.3% (8,896/ 121,224) of patients in the control I group had peptic ulcers (P < 0.001). The depression group had an adjusted HR for peptic ulcers that was 1.14-fold higher than that of the control I group (95% confidence interval [95% CI] = 1.09-1.19, P < 0.001). A total of 6.4% (8,144/ 127,590) of peptic ulcer patients and 3.5% (4,515/127,590) of patients in the control II group had depression (P < 0.001). The peptic ulcer group had an adjusted HR for depression that was 1.68-fold higher than that of the control II group (95% CI = 1.62-1.74, P < 0.001). Depression and peptic ulcers exhibited a bidirectional relationship.