The placebo effect in Parkinson's disease

Trends Neurosci. 2002 Jun;25(6):302-6. doi: 10.1016/s0166-2236(02)02181-1.


The biochemical bases of the placebo effect are still incompletely known. We show here that the placebo effect in Parkinson's disease is due, at least in part, to the release of dopamine in the striatum. We propose that the placebo effect might be related to reward mechanisms. The expectation of reward (i.e. clinical benefit) seems to be particularly relevant. According to this theory, brain dopamine release could be a common biochemical substrate for the placebo effect encountered in other medical conditions, such as pain and depression. Other neurotransmitters or neuropeptides, however, are also likely to be involved in mediating the placebo effect (e.g. opioids in pain disorders, serotonin in depression).

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Corpus Striatum / metabolism*
  • Dopamine / metabolism*
  • Humans
  • Parkinson Disease* / metabolism
  • Placebo Effect*
  • Randomized Controlled Trials as Topic
  • Tomography, Emission-Computed


  • Dopamine