Major depressive disorder increases risk of irritable bowel syndrome, reveals research

A new study published in the Journal of Affective Disorders demonstrated the causal relationships between major depressive disorder (MDD), schizophrenia and irritable bowel syndrome (IBS) which has been debated for decades.

There has been a lot of attention in the connection between neurological illnesses and IBS because of the possible role the gut-brain axis plays in pathophysiological pathways. IBS and mental problems have been strongly linked in previous research by indicating that stress may either cause or exacerbate IBS. In the light of a comprehensive study, the individuals with IBS and mental illness have more severe and incapacitating gastrointestinal symptoms. According to recent epidemiological statistics, one-third of patients had psychological problems prior to IBS, and two-thirds of individuals had IBS before psychological problems. A 2023 study that looked at the frequencies of psychiatric disorders in 1.2 million hospitalizations of IBS patients discovered that more than 38% of them had anxiety and more than 27% had depression.

The majority of the summary data from genome-wide association studies (GWASs) came from a recent GWAS on IBS and from the Psychiatric Genomics Consortium (PGC) on people of European ancestry. Weighted median (WM), inverse-variance weighting (IVW), and MR-Egger regression (MR-Egger) were the three MR techniques we employed. Two additional indicators were also employed to detect directional horizontal pleiotropy and evaluate heterogeneity: the MR-Egger intercept and the MR-IVW Cochran's Q statistic.

The study found that bipolar illness (81.18 %, 95% CI = 73.18-148.18 %), schizophrenia (33.88%, 95% CI = 33.57-38.19 %), and panic disorder (30.66 %, 95% CI = 20.74-40.58 %) all showed high heritability. Regarding other diseases, major depressive disorder (MDD) (0.67 %, 95% CI = 0.61-0.73 %), anxiety disorder (7.63 %, 95% CI = 1.67-13.59 %), PTSD (0.96 %, 95% CI = 0.12-1.8 %), and IBS (2.44 %, 95% CI = 2.13-2.75 %) all showed modest liability-scale SNP heritability. Additionally, the found that MR-IVW significantly demonstrated the causal relationship between schizophrenia and IBS. There were no pleiotropic effects found, despite the fact that the individual causative estimations of genetic instruments for schizophrenia and MDD were varied. Overall, this research emphasize the necessity of a thorough care plan in clinical practice that takes gastrointestinal and mental symptoms into account.

Source:

Fan, W., Liu, Y.-L., Jiang, C.-H., Wu, H., Jin, J., He, Z.-X., Kang, L., & Fang, X. (2024). Association between psychiatric disorders and irritable bowel syndrome: A bidirectional Mendelian randomization study. In Journal of Affective Disorders. Elsevier BV. https://doi.org/10.1016/j.jad.2024.09.030