Role of Anxiety and Depression on the Interplay Between Disorders of Gut-Brain Interaction and Eating Disorders

Background: Disorders of gut-brain interaction (DGBI) are frequently encountered among patients with eating disorders (ED). Underlying both eating disorders and DGBI may be psychological co-morbidities, but it is uncertain how often psychological disorder explains the development of either disorder. We hypothesised a DGBI may predispose to a new onset eating disorder. We aimed to determine the associations and chronological presentation of DGBI, ED and psychological co-morbidities. Methods: Data were collected from a retrospective cohort of n =1,256,331 patients attending general practices in the UK; 1018 patients diagnosed with both a DGBI and an ED were included, with 777 also having data on anxiety and/or depression. Timing of order of onset and potential moderators of the sequence of occurrence were considered. Clinical significance level was set at p <0.01 and OR≥ 2.0. Results: Prevalence of any ED was 0.7%. Chronic constipation was associated with anorexia nervosa (OR= 2.12 (95% CI 1.84-2.45) and any eating disorder (OR= 2.06 (95% CI 1.79-2.36). IBS and FD were significantly associated with one or more eating disorders. More patients in primary care were diagnosed with an ED (59.5%, n=606) preceding a DGBI than vice versa (40.5%, n=412, P<0.001). Independent predictors of having a diagnosed DGBI preceding an ED were younger age at first diagnosis of DGBI (P<0.001), antecedent depression (P<0.003) and antecedent proton pump inhibitor (PPI) use (P<0.001). Conclusion: Psychological disorders, ED, and DGBI overlap. ED more frequently preceded the onset of a DGBI diagnosis; younger age, antecedent depression and PPI use were independently associated with a DGBI predicting an ED.