[gwern]

The prior probability was always low. And it is not as if any of the followup experiments or surveys have reported much better results, you know. A charitable assessment of past LSD microdosing experiments in humans, https://www.biorxiv.org/content/early/2018/08/11/384412 https://harmreductionjournal.biomedcentral.com/articles/10.1... https://journals.plos.org/plosone/article?id=10.1371/journal... https://link.springer.com/article/10.1007%2Fs00213-018-5119-... https://www.gwern.net/docs/nootropics/2019-bershad.pdf , might be that "the evidence is consistent with scattered small benefits which do not line up with the large effects claimed in self-report data or the microdosing community's claims".

This doesn't much change the summary. Even at face-value (though you have to wonder about losing 80% of their data), what functional changes does some transient blood serum increases in BDNF cause, and why would some chemical results noticeably change one's assessment of the experimental evidence reported so far? It will be much more interesting to read the other data, which, however, remains unknown: "assessment of mood, cognition, empathy, and creativity that will be reported elsewhere." (That's from the pain paper reporting this study. Apparently they intend to salami-slice this study into at least 3 papers.)