{Reference Type}: Journal Article {Title}: Causal mediation analysis: How to avoid fooling yourself that X causes Y. {Author}: Lazic SE; {Journal}: Lab Anim {Volume}: 0 {Issue}: 0 {Year}: 2024 Aug 11 {Factor}: 2.908 {DOI}: 10.1177/00236772231217777 {Abstract}: The purpose of many preclinical studies is to determine whether an experimental intervention affects an outcome through a particular mechanism, but the analytical methods and inferential logic typically used cannot answer this question, leading to erroneous conclusions about causal relationships, which can be highly reproducible. A causal mediation analysis can directly test whether a hypothesised mechanism is partly or completely responsible for a treatment's effect on an outcome. Such an analysis can be easily implemented with modern statistical software. We show how a mediation analysis can distinguish between three different causal relationships that are indistinguishable when using a standard analysis.