Question special
Lead Moderator

Another important issue raised by the study of Mathieson and colleagues is the placebo effect which was quite substantial here (pain intensity decreased for about 50 % in the placebo group). Amazingly the placebo effect in neuropathic pain clinical trials has substantially increased particularly in studies using gabapentin and pregabalin over the past years, while the effects of the active drug seems to be stable over time (Tuttle, Pain. 2015;156 :2616-26.). This may underestimate treatment effects (see PLoS One. 2014 ;9:e84104). Large scale studies seem to be associated with higher placebo responses than smaller ones, but other predictors based on pain characteristics at baseline have been identified.
I would be interested to know your opinion about this. Do you think that it may be possible to predict the placebo response in trials of chronic pain ? Would you encourage the design of studies using an initial placebo run in phase for example ? Do you have other suggestions?