Abstract

The gut-brain axis is responsible for bidirectional communication between the gastrointestinal (GI) system and the brain. Mental health conditions (MHCs) such as anxiety, depression, or Post-Traumatic Stress Disorder (PTSD), a psychiatric condition that develops after someone experiences a traumatic event, have been shown to disrupt this communication, leading to worsened patient outcomes with overall increased risk of developing comorbid gastrointestinal disorders. This crosssectional study examined admissions nationwide through the use of health insurance claims data from 2014 to 2021 to investigate how comorbid MHCs and disorders of the gut-brain interaction (DGBIs) or Inflammatory Bowel Disease (IBD) influence hospital outcomes in adolescents and young adults (AYAs) aged 14 to 24 years. Using a three-cohort comparison based on the presence of MHCs and DGBI/IBD diagnoses, we categorized 911,648 cases into three distinct cohorts (Vizient, 2025). Notably, our analysis identified zero documented PTSD admissions within the sample. Given established prevalence rates, this anomaly may suggest systemic issues with diagnostic coding or data capture in admissions. The MHC+GI+ group demonstrated significantly worse clinical outcomes, with increased length of stay (11.6 days), longer time spent in the Intensive Care Unit (9.3 days), highest cost variation (±60830.74, $8,421.2), and higher mortality (0.7%) in comparison to other groups, although complication rates were slightly lower (3.4%), (all p<0.0001). These findings emphasize the connection between DGBI/IBD and MHC comorbidity, as well as their association with worse clinical outcomes, when compared to an independent DGBI/IBD or MHC diagnosis.

How to Cite:

Brown, E. M., (2026) “Patterns of Risk Across Three Cohorts: Mental Health Conditions, Gastrointestinal Disorders, and Comorbidity in 14- to 24-year-olds”, Arizona Journal of Interdisciplinary Studies 12(1), 11-22.