Depression and 24 gastrointestinal diseases: a Mendelian randomization study

Area of Science:

• Gastroenterology
• Psychiatry
• Genetics

Background:

• The causal relationship between depression and gastrointestinal diseases remains unclear.
• Previous studies suggest associations, but causality is difficult to establish due to confounding factors.

Purpose of the Study:

• To investigate the potential causal role of depression in the development of 24 distinct gastrointestinal diseases.
• To explore mediating factors such as body mass index, smoking, and type 2 diabetes in these associations.

Main Methods:

• Utilized Mendelian randomization (MR) analysis, a robust genetic epidemiology technique.
• Selected independent genetic variants associated with depression as instrumental variables.
• Analyzed genetic associations with 24 gastrointestinal diseases using data from UK Biobank, FinnGen, and large consortia.

Main Results:

• Found genetic liability to depression significantly associated with increased risks for irritable bowel syndrome, non-alcoholic fatty liver disease, alcoholic liver disease, gastroesophageal reflux, chronic pancreatitis, duodenal ulcer, chronic gastritis, gastric ulcer, diverticular disease, cholelithiasis, acute pancreatitis, and ulcerative colitis.
• Identified body mass index as a significant mediator for the effect of depression on non-alcoholic fatty liver disease.
• Determined that genetic predisposition to smoking initiation mediated approximately half of the effect of depression on acute pancreatitis.

Conclusions:

• Depression may exert a causal influence on the pathophysiology of a wide spectrum of gastrointestinal diseases.
• The findings highlight the complex interplay between mental health and digestive system disorders.
• Suggests potential targets for therapeutic interventions addressing both depression and gastrointestinal health.