Yes! Here is some I managed to quickly dig up:
- https://www.nature.com/articles/d41586-022-02876-5
- https://pubmed.ncbi.nlm.nih.gov/33648632/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6364961/
- https://pubmed.ncbi.nlm.nih.gov/34915762/
- https://pubmed.ncbi.nlm.nih.gov/35918311/
BIG DISCLAIMER before you read the next bits: I'm not a researcher/scientist in this field, but psychedelics have helped me get a handle on CPTSD, process trauma.
My take on this is that microdosing probably still has some acute benefits, since it still does alters brain chemistry. So, can it be helpful? Probably, but it should come with a big "YMMV" disclaimer.
In the context of psilocybin, my understanding is that it doesn't give long-term benefits as a "macro" dose would like DMN regulation[1] and neuroplasticity[2]; a lot of people tend to attribute these to microdosing too, but apparently it's not the case[3]. Also, due to tolerance build up, so you start getting diminishing returns from microdosing, so it's not effective long-term (even with the Fadiman microdosing protocol where you take breaks; I think there's other protocols that claims to lessen the diminishing returns). I don't think LSD triggers these physiological changes in the brain, but it's believed it can helps with the psychological aspects.
I don't take them regularly anymore (I used to take them every couple of months during a rough patch in my life, but I also did therapy on-and-off during that period too). I now take them every few years as to check-in with myself, or special occasions.
[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10032309
[2]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6082376; I feel like there was a another study on this too, but I can't find it now, sorry!
[3]: Only briefly discussed by Huberman in his podcast: https://www.youtube.com/watch?v=eIxVfln02Ss. I recommend watching the video in its entirety; it's great!