Comment on

• Placebos and placebo effects in medicine: historical overview.

  de Craen AJ, Kaptchuk TJ, Tijssen JG, Kleijnen J. de Craen AJ, et al. J R Soc Med. 1999 Oct;92(10):511-5. doi: 10.1177/014107689909201005. J R Soc Med. 1999. PMID: 10692902 Free PMC article. No abstract available.
• The placebo effect and endogenous opioids.

  Sher L. Sher L. J R Soc Med. 2000 Mar;93(3):158. doi: 10.1177/014107680009300315. J R Soc Med. 2000. PMID: 10741321 Free PMC article. No abstract available.