Mendelian Randomization for Nutritional Psychiatry

Nutritional psychiatry is a growing area of research, with several nutritional factors implicated in the aetiology of psychiatric ill health. However, nutritional research is highly complex, with multiple potential factors involved, highly confounded exposures and small individual effect sizes. This paper considers whether Mendelian randomization provides a solution to these difficulties, by investigating causality in a low risk and low-cost way. Current studies using MR in nutritional psychiatry are reviewed, along with the potential opportunities and challenges of using this approach for investigating the causal effects of nutritional exposures. Several studies have identified potentially causal nutritional exposures using Mendelian randomisation in psychiatry, offering opportunities for further mechanistic research, intervention development, and replication. Using Mendelian randomisation as a foundation for intervention development allows the best use of resources in an emerging discipline in which opportunities are rich, but resources are often poor.