Expectation and dopamine release: mechanism of the placebo effect in Parkinson's disease

R De la Fuente-Fernández, TJ Ruth, V Sossi… - Science, 2001 - science.org
R De la Fuente-Fernández, TJ Ruth, V Sossi, M Schulzer, DB Calne, AJ Stoessl
Science, 2001science.org
The power of placebos has long been recognized for improving numerous medical
conditions such as Parkinson's disease (PD). Little is known, however, about the mechanism
underlying the placebo effect. Using the ability of endogenous dopamine to compete for
[11C] raclopride binding as measured by positron emission tomography, we provide in vivo
evidence for substantial release of endogenous dopamine in the striatum of PD patients in
response to placebo. Our findings indicate that the placebo effect in PD is powerful and is …
The power of placebos has long been recognized for improving numerous medical conditions such as Parkinson's disease (PD). Little is known, however, about the mechanism underlying the placebo effect. Using the ability of endogenous dopamine to compete for [11C]raclopride binding as measured by positron emission tomography, we provide in vivo evidence for substantial release of endogenous dopamine in the striatum of PD patients in response to placebo. Our findings indicate that the placebo effect in PD is powerful and is mediated through activation of the damaged nigrostriatal dopamine system.
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