Placeo effects occur. They are a problem for clinical trials. For some illnesses they may offer short term gains, but at the cost of a worse prognosis. But, for everyday Parkinson's I believe they offer a wonderful opportunity.

The engineer in me says let's maximise the benefit. I describe how I think it can be done in:
http://neurotalk.psychcentral.com/sh...hlight=placebo

I observe that this forum behaves in a similar way.

John