At Azarius we love to read any scientific news on weed. Especially in a reputable magazine like New Scientist. According to this article our ancestors were already into the high life.
"The researchers suggest that different groups of people across the Eurasian landmass independently began using the plant at this time – perhaps for its psychoactive properties or as a source of food or medicine, or even to make textiles from its fibres."
The article is full of interesting suggestions for further research. And if you are really into the subject you can find the study 'Cannabis in Eurasia: origin of human use and Bronze Age trans-continental connections' here.
Also don't forget the work of Terence and Dennis McKenna who did a lot of similar research concerning the prehistoric use of mushrooms.