The health care systems of the U.K., Finland, and Sweden have each conducted systematic, comprehensive reviews of the safety and effectiveness of puberty-blockers and cross-sex hormones on adolescents with gender dysphoria. Such reviews are the standard procedure when developing health care policy. All three reviews concluded that there is little evidence of benefit off-setting the known and unknowns risks of medicalized transition of minors.
In updating its Standards of Care (version 8), WPATH published its own review of effectiveness (Baker et al., 2021). Unlike Europe, however, that review did not include safety in the scope of the review and came to this very positive (if qualified) conclusion about effectiveness:
If one wanted simply to advocate for medicalized transition, one would just quote the highlighted portion of the abstract and call it a day. A good researcher, however, would continue to the actual data tables to search for the source of the contradiction.
That source wasn't hard to find. The article showed the outcomes across three tables, one each for transition results on quality of life (QOL), on depression, and on anxiety:
Effects of Gender-Affirming Hormone Therapy on Anxiety Among Transgender People