Gastroesophageal Reflux Disease and Risk for Bipolar Disorder: A Nationwide Population-Based Study

Background: Studies have shown that chronic inflammation may play a vital role in the pathophysiology of both gastroesophageal reflux disease (GERD) and bipolar disorder. Among patients with GERD, the risk of bipolar disorder has not been well characterized. Objective: We explored the relationship between GERD and the subsequent development of bipolar disorder, and examined the risk factors for bipolar disorder in patients with GERD. Methods: We identified patients who were diagnosed with GERD in the Taiwan National Health Insurance Research Database. A comparison cohort without GERD was matched according to age, sex, and comorbidities. The occurrence of bipolar disorder was evaluated in both cohorts based on diagnosis and the prescription of medications. Results: The GERD cohort consisted of 21,674 patients, and the comparison cohort consisted of 21,674 matched control patients without GERD. The incidence of bipolar disorder (incidence rate ratio [IRR] 2.29, 95% confidence interval [CI] 1.58-3.36, P < .001) was higher among GERD patients than among comparison cohort. Multivariate, matched regression models showed that the female sex (hazard ratio [HR] 1.78, 95% CI 1.76-2.74, P = .008), being younger than 60 years old (HR 2.35, 95% CI 1.33-4.16, P = .003), and alcohol use disorder (HR 4.89, 95% CI 3.06-7.84, P = .004) were independent risk factors for the development of bipolar disorder among GERD patients. Conclusions: GERD may increase the risk of developing bipolar disorder. Based on our data, we suggest that attention should be focused on female patients younger than 60 years, and patients with alcohol use disorder, following a GERD diagnosis.