Years ago I had dinner with a psychiatric professor at UCLA. He said we don’t know what antidepressants do or why they work or why they don’t. A recent study concludes its even worse than that
Although “the serotonin hypothesis of depression is still influential,” Moncrieff and coauthors noted, citing widely adopted textbooks published as recently as 2020 and surveys indicating that “85-90 percent of the public believes that depression is caused by low serotonin or a chemical imbalance,” the primary research indicates there is “no support for the hypothesis that depression is caused by lowered serotonin activity or concentrations.”
Read the whole thing
memoirandremains 
Fascinating