Exploring the Role of Brain Fog, Fatigue, and Psychological Distress on Quality of Life in Individuals Living with Inflammatory Bowel Disease: A Cross-sectional Study.

Background and aims: Despite reports of brain fog in patients with inflammatory bowel disease (IBD), empirical research into this phenomenon has been lacking. This study aimed to validate a brain fog scale and explore the relationships between IBD symptom activity, brain fog, fatigue, psychological distress, and quality of life (QoL).

Method: A cross-sectional online study.

Results: Of the 170 adults with IBD (mean age 38.75 years, 85.9% female, 62.35% Crohn's disease), 94.10% percent reported experiencing brain fog, with the majority (53.75%) experiencing brain fog at least 2 times a week, with each episode lasting around 2 hours. A confirmatory factor analysis supported the first hypothesis, demonstrating validity and stability of the brain fog scale in an IBD sample. Correlation analyses supported the second hypothesis, revealing positive relationships between IBD symptom activity and brain fog, fatigue and psychological distress, and a negative relationship between IBD symptom activity and QoL. A structural equation model with excellent fit (CMIN/df=1.84, p=0.137, TLI=0.98, CFI=0.99, SRMR=0.03, and RMSEA=0.07), provided support for the third hypothesis in that the relationship between IBD symptom activity and QoL was fully mediated by brain fog, fatigue, and psychological distress.

Conclusions: This is the first study to explore the lived experience of brain fog and to validate the brain fog scale in an IBD sample. The study provides evidence that like fatigue, brain fog is not only common in IBD cohorts but is also frequent and adversely impacts psychological distress and QoL.