i am sure there are others here who know much more about this, but the two criticisms i have heard of the Gill/Bristol study are:

1) the dosages of levodopa (and other drugs, possibly) were tweaked during the study, and
2) it was open label, and i guess there is another one
3) there were only five participants, i think

but upon thinking about #1 above, i have read plenty of studies that allow levodopa to be added to, say, the dopamine agonist arm of a study that is meant to be comparing the time-to-dyskinesias with the dopamine agonist vs with levodopa - that is standard procedure, as far as i can tell (ridiculous though it seems) - and if that is so, then how can the bristol study be faulted for tweaking levodopa? seems to me they can both be faulted or neither, but one and not the other doesn't seem to make sense to me.

the second two make sense to me - it has always seems like a big waste of money to me to do an open label clinical trial that is meant to evaluate anything but safety... well, i suppose if one observed zero effect, that would tell you something but what are the chances of that, given the power of the placebo effect?

any input would be appreciated, boann

p.s. rosebud, i have the study in pdf, if you would like to read it - i would be happy to send it. let me know.