Yes, a crossover trial design would be one way to address that. For example, various side effects have long been attributed to statins. This was tested in a tri

Yes, a crossover trial design would be one way to address that. For example, various side effects have long been attributed to statins. This was tested in a trial published very recently in a placebo controlled crossover design, which found that the effect attributed to statins has probably been overestimated[1]. (They found no significant difference between placebo and statin; but, by eye, I would be willing to agree with a skeptic that it looks like there is probably a difference that is just too modest to identify at statistical significance at this sample size.) I should add that the original article being discussed is making claims that would not require any crossover trial to identify. If lowering cholesterol doesn't cause numerically higher suicide or depression, then the author's point is invalidated. 1 = https://www.jacc.org/doi/10.1016/j.jacc.2021.07.022 https://www.jacc.org/doi/10.1016/j.jacc.2021.07.022