Girija, I think you mentioned length of trial - maybe the trials aren't long enough. PRECEPT was halted after I'd been in it for 2 years - and I was SUPPOSED to have been in it for 3 years. I can't list many recent trials that have gone that long.

And Debi, if you are right that the placebo effect may last over a year, then it seems logical to me that PD trials should be set up for longer periods.