Against the Placebo Effect. Contra my article on the placebo effect:

The picture that emerges is that a placebo pill has almost no effect when administered by researchers who do not care about the placebo effect, but the exact same pill has an enormous effect larger than all existing treatments when administered by a researcher who really wants the placebo effect to be real. The most parsimonious explanation is that it is the research practices, rather than the placebo.

Impressively comprehensive, but not super strong—a lot of digging here. That said, it does emphasise how unreliable the placebo is, as are efforts to find it. It seems likely that the mechanism is not singular.