Gastrointestinal health: An investigation of mediating effects on mood and quality of life.

High prevalence rates for depression, anxiety, and gastrointestinal (GI) symptoms are found in emerging adults. However, the consequences of mood, anxiety, and GI health on health-related quality of life (HRQOL) are not well established. The biopsychosocial model and the gut-brain axis (GBA) explains the interactions of these psychological phenomenon on social and biological functioning. Following this theoretical framework, it was hypothesized that pathways between depression, anxiety, and HRQOL would be mediated by GI health. Data was cross-sectional. Undergraduates in psychology courses (N = 956) were recruited for course credit as part of ongoing research monitoring physical and psychological health of students at a major southeastern university. Participants were between 18 and 25 years old and measures were administered online. Pathways between depression, anxiety, and HRQOL were investigated using SEM analysis. The SEM was tested and specified for mediating effects. A well-fitting latent variable of GI health was created from the PROMIS-GI® scales, advancing its utility. The mediation model demonstrated anxiety and depression have significant consequences for HRQOL in emerging adults. Direct pathways from GAD7 and PHQ9 scores were found between Physical and Mental HRQOL. Notably, the path from anxiety to Physical HRQOL was fully mediated by GI health. The direct path from depressive symptoms to Physical and Mental HRQOL was partially mediated by GI health, and anxiety to Mental HRQOL was partially mediated by GI health. Findings were consistent with the biopsychosocial model and GBA. The mediation model tested here has treatment and conceptual implications. Individuals presenting with anxiety or depression should be assessed for GI symptoms and conversely, those presenting with GI complaints should be evaluated for anxiety and depression. Research is needed to develop a scoring approach to combine the PROMIS-GI® scales, so the latent construct of GI health may be used in related applications.