Psychiatric comorbidities among adult patients with disorders of gut–brain interaction: Prevalence and relationships to treatment outcomes

Background: Little is known about the impact of psychiatric comorbidity on pharmacologic treatment outcomes, including neuromodulators (medications targeting the gut–brain axis), among adult patients with disorders of gut–brain interaction (DGBI). Accordingly, we aimed to examine associations between psychiatric comorbidity and DGBI pharmacologic treatment outcomes. Methods: In a retrospective study of consecutively referred new patients (N = 410; ages 18–90; 73% female) to a tertiary neurogastroenterology clinic in 2016 with follow-up through 2018, relationships between psychiatric illness (any psychiatric illness, anxiety disorders, depressive disorders) and pharmacologic treatment selection (any medication, neuromodulating medication) and treatment outcomes, respectively, were examined using multivariable logistic regression, adjusting for demographics, gastrointestinal (GI) diagnoses, and pre-existing neuromodulator use. Key Results: Anxiety disorders (35%) were the most common psychiatric comorbidity, followed by depressive disorders (29%). Patients with anxiety disorders were more likely to be prescribed a neuromodulator by their gastroenterologist (OR = 1.72 [95% CI 1.10–2.75]) yet less likely to respond to neuromodulators (OR = 0.43 [0.21–0.90]) or any GI medication (OR = 0.24 [0.12–0.50]) in fully adjusted analyses. In contrast, depressive disorders were not associated with neuromodulator prescription or response. Conclusions and Inferences: Anxiety disorders are common among patients with DGBI and significantly reduce the likelihood of GI pharmacologic treatment response to any medication prescribed, including neuromodulators.