Related Experiment Video
Updated: Jan 11, 2026
Chronic Salmonella Infection Induced Intestinal Fibrosis
Published on: September 22, 2019
Causal Relationship Between Inflammatory Bowel Disease and Neuropsychiatric Disorders: A Bidirectional Mendelian
Jiawei Lei1, Liping Gong1, Shan Wei1
1Department of Gastrointestinal and Burn Surgery, The First Affiliated Hospital of Hunan Traditional Chinese Medical College (Hunan Provincial Directly Affiliated Hospital of Traditional Chinese Medicine), Zhuzhou, China.
Background:
Observational studies have indicated a correlation between inflammatory bowel disease (IBD) and neuropsychiatric disorders, yet the causal relationship remains unclear.
Objective:
We aim to employ two-sample Mendelian randomization (MR) to ascertain the potential causal relationship between IBD and seven major neuropsychiatric disorders.
Methods:
We conducted a bidirectional two-sample MR analysis utilizing genome-wide association study (GWAS) summary statistics of European ancestry for IBD (31,665 cases and 33,977 controls) and its subtypes, ulcerative colitis (UC, 13,768 cases and 33,977 controls) and Crohn's disease (CD, 17,897 cases and 51,874 controls), along with seven major neuropsychiatric disorders: major depressive disorder (MDD, 135,458 cases and 344,901 controls), bipolar disorder (BD, 41,917 cases and 371,549 controls), schizophrenia (SCZ, 33,640 cases and 43,456 controls), Alzheimer's disease (AD, 39,106 cases and 46,828 controls), Parkinson's disease (PD, 33,674 cases and 449,056 controls), multiple sclerosis (MS, 14,498 cases and 24,091 controls), and amyotrophic lateral sclerosis (ALS, 27,205 cases and 110,881 controls).
Results:
Our analysis revealed potential positive causal effects of IBD and CD on MDD and SCZ. Similarly, SCZ was positively correlated with an increased risk of IBD and UC. There was a bidirectional positive association between IBD, UC, and MS, whereas CD showed a positive causal effect on MS. Similar to the investigation of the seven specified neuropsychiatric disorders on CD, we did not find evidence supporting causal effects of MDD, BD, AD, PD, or ALS on IBD or UC. Sensitivity analyses further reinforced the robustness of the MR estimates.
Conclusion:
Our results support potential causal relationships between IBD (including its subtypes CD and UC) and several neuropsychiatric disorders, reinforcing the gut-brain axis concept and enhancing our understanding of extra-intestinal manifestations of IBD and neuropsychiatric manifestations in the context of IBD.
Related Concept Videos
01:17Irritable Bowel Syndrome I: Introduction
IBS is a chronic condition that can persist over a long period or recur frequently.
The pathogenesis of IBS involves a complex interplay of the following factors:
Altered...
01:17Chronic Bowel Disorders: Introduction
Irritable Bowel Syndrome (IBS) is a common disorder affecting the gastrointestinal tract. The distinctive feature is recurrent abdominal pain associated with altered bowel movements, manifesting as constipation, diarrhea, or fluctuating between both. The...
01:30Inflammatory Bowel Disease II: Crohn's Disease
Inflammatory bowel disease, commonly known as IBD, refers to a collection of disorders that lead to persistent inflammation of the gastrointestinal tract. The two types of IBD are ulcerative colitis, which impacts the colon, and Crohn's disease, which can involve any part of the gastrointestinal segment.
Crohn's disease
Crohn's disease is a chronic, systemic inflammatory bowel disease (IBD) that predominantly affects the gastrointestinal tract. It is marked by...
01:30Inflammatory Bowel Disease III: Diagnostic Studies and Management I-Nutritional Therapy
Diagnostic studies
A colonoscopy is the definitive screening test, distinguishing ulcerative colitis from other colon diseases with similar symptoms. During a colonoscopy test, inflamed mucosa with exudate ulcerations can be observed, and biopsies are taken to determine the histologic characteristics of the...
01:27Inflammatory Bowel Disease I: Ulcerative Colitis
Inflammatory bowel disease, or IBD, encompasses a group of disorders characterized by chronic inflammation or ulceration of the gastrointestinal tract.
Risk Factors
The exact cause of IBD remains unclear, although it is believed to be due to a mix of genetic, environmental, microbial, and immune factors. Genetic factors are significant in determining susceptibility to IBD, with family history being a critical risk factor. Individuals with a first-degree relative who has IBD are at...
01:27Psychoneuroimmunology: Cardiovascular Disease
A key area of focus in PNI is the relationship between stress and coronary...