Scott Alexander critically examines a new theory on antidepressant mechanisms, expressing skepticism while acknowledging its potential significance if proven true. Longer summary

Scott Alexander reviews a recent study proposing a new theory for how antidepressants work, which suggests they bind directly to TrkB receptors rather than acting through serotonin. He explains the study's findings and their potential implications, but expresses skepticism about the theory. Scott outlines several reasons why he finds the new theory unconvincing, including existing evidence supporting the serotonin hypothesis, issues with the study's claims about drug accumulation, and expert opinions on the difficulties of TrkB research. He concludes by stating he will stick with the conventional theory for now, while remaining open to future developments. Shorter summary