Is Pot Far More Potent Than in the Past? No.

The Ottawa Citizen comes through in this article by Dan Gardner yesterday.
Gardner takes apart all the claims of massive increases in potency, and shows that it’s a combination of different measuring techniques, and the range of higher and lower THC concentrations that have always been available, with a conclusion that there have been some overall average increases in potency due to better horticultural techniques, but not the levels claimed by prohibitionists.
He then goes on to debunk Walters’ implied link to increased treatment and emergency room statistics, and concludes with a section on how smokers automatically self-regulat:

Mr.æ Earleywine notes that surveys asking users how high they get show no change since the 1970s, despite the increase in marijuana potency.æ “It’s just that they’re smoking less of it, rather than getting higher.”

Oddly enough, this suggests that rising marijuana potency may produce a modest health benefit.æ “When smoking stronger pot, you smoke less and you have less exposure to tars and respiratory irritants,” Mr.æ Earleywine says, adding with a laugh, “so in some ways it’s worth smoking the best pot you can afford.”

Then today, Gardner finishes up with part 2: How Science Is Skewed to Fuel Fears of Marijuana in which he takes on the junk science and bad reporting that add to misconceptions about pot.
For example, recent claims that link marijuana to psychosis have gotten some major press, particularly in England. Yet, Gardner notes that the methodology is potentially suspect (subjects were not evaluated for psychosis, but merely asked a series of questions, including: feeling that other people cannot be trusted; feeling that you are being watched or talked about by others; never feeling close to a person; and having ideas and beliefs that others do not share. Some of these could be more a result of the illegality of marijuana than any indications of psychosis.
And even with this suspect methodology, the scientists who ran the study themselves are not happy with the press coverage:

“It is quite clear that media claims that our research shows cannabis use causes psychosis are exaggerated,” Mr.æ Fergusson says.æ

Science is being subordinated to politics, Mr.æ Fergusson feels.

Good articles.