The main areas of serotonin research provide no consistent evidence of there being an association between serotonin and depression, and no support for the hypothesis that depression is caused by lowered serotonin activity or concentrations.

I’ll often say something like the way Zoloft works, is, it increases the level of serotonin in your brain (or synapses, neurons) and, presumably, the reason you’re depressed or anxious is that you have some sort of a deficiency. And I say that [chuckles] not because I really believe it, because I know the evidence really isn’t there for us to understand the mechanism—I think I say that because patients want to know something. And they want to know that we as physicians have some basic understanding of what we’re doing when we’re prescribing medications. They certainly don’t want to know that a psychiatrist essentially has no idea how these medications work

Smith and I found that, of the nearly 1,800 articles published across the four editions of the encyclopedia, only 13 addressed racism in a substantive way.