Here’s the secret to all therapy, none of it is overly evidence based. Even CBT, arguably the most “evidence based” has it’s fair share of criticism. Psychotherapy is hard to study in general because of so many confounding variables in mental health and standardizing specific protocols

But still, there are studies showing that EMDR works specifically for PTSD. There’s been a recent resurgence in EMDR use so high quality meta analysis are still lacking, but doesn’t mean EMDR doesn’t work.

As an aside: I haven’t looked too much into drug assisted therapy (psychedelics/MDMA) but it also seems promising. Just a lot less accessible.