That is very interesting. The value of double blind studies is to eliminate bias by preventing everyone involved from knowing which is the study group and which is the control. I would have thought that in a study of a psychoactive drug, it would be immediately apparent which group had received the placebo.
This is yet more evidence that marijuana is not as harmless as its legalization advocates have claimed.
ROTFL! Seriously?! Real marijuana is harmful because fake marijuana makes some people think they're stoned?!?
No. The result of this study was that significantly more people in the test group had paranoid thoughts than the people in the control group (whether they experienced the placebo effect or not).
This was a short term study. Long term studies are showing deleterious effects of marijuana use, even 2 years after the last use. Furthermore, marijuana has been shown to precipitate psychotic disorders in non-mature brains; this short term study supports this finding. The brain finishes developing at about 25 years.