The role of gut microbiota in common psychiatric disorders in middle and old age

Psychiatric disorders are a leading cause of the global burden of health.

Depression, anxiety, and stress-related disorders are common psychiatric disorders, with a higher prevalence in women than in men. The microbiota-gut-brain axis has been proposed as a candidate mechanism underlying mental disorders.

However, the evidence on if gut microbiome is associated with the risk of depression, anxiety, and stress-related disorders, as well as treatment response to antidepressants is sparse.

The proposed project aims to study (1) if gut microbiome is associated with depression, anxiety, and stress-related disorders, (2) if genetic predisposition to these diseases modifies such association, and (3) if gut microbiome is associated with treatment response to antidepressants. This project will be a 3-year collaboration between Sweden and the USA, starting from July 2023.

I will address the three aims in two Swedish cohorts (n=17,131) and verify the findings in a US cohort (n=20,000).

The three cohorts are currently the largest databases with data on gut microbiome, common psychiatric disorders, and antidepressant use in the world.

They also contain comprehensive and high-quality data on important covariables via linkages to national registers as well as self-reported information from questionnaires.

Findings from the project will provide novel understanding on the role of gut microbiome in common psychiatric disorders and contribute to personalized medicine in antidepressant use.