Pro trans activists like to cite cornell literature review to support their claim that gender transition has a positive effect on transgender wellbeing, but the problem is that studies that proclaim that are of poor quality (most of them have small sample sizes and no controls)

https://www.thepublicdiscourse.com/2019/04/51524/

Also see this article by Sean that talks about more trans related stuff https://ideasanddata.wordpress.com/2021/02/07/on-transgenderism/