I know that there's been discussion about the placebo effect on this board, and I'm aware that it has been reported as being common in Parkinson's patients as well.
Not sure whether you all will be able to access this outside of the UK but this program shown last night was very interesting. Although it looks primarily at patients with pain I think it is still relevant. Hope it might be of interest to some.
bbc.co.uk/iplayer/episode/b...
Nick