Some links and sources from the episode:

* If you know you're receiving a placebo, it still works (https://www.health.harvard.edu/blog/placebo-can-work-even-know-placebo-201607079926)

* The nocebo effect is like the placebo effect's evil twin (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1187870/)

* In fact, it may have been implicated in the death of a lot of Hmong people (https://www.theatlantic.com/health/archive/2011/09/the-dark-side-of-the-placebo-effect-when-intense-belief-kills/245065/)

* A nice visualization of things that aren't placebos compared to those that are

* Classical conditioning and the placebo effect (https://www.ncbi.nlm.nih.gov/pubmed/9272794)

* You can even condition your immune system (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3504052/)