You are probably right about setting. One of the papers that the Wired article links to talks about the importance of good lighting.

The article made it to digg!
Digg - Scientists now Understand How Weed Causes Paranoia
SoyChemist Reviewed by SoyChemist on . Wired Explains the Science of a Paranoid High In the January issue of Neuropharmacology, which happens to have a marijuana theme, two teams of researchers tried to explain what causes some people to feel relaxed when they smoke weed while others get a paranoid high. Wired has explained those articles. Check it out! http://blog.wired.com/wiredscience/2008/01/chem-lab-the-sc.html Do you think that there is something in bad weed that causes paranoia and does good weed not have that stuff? Rating: 5