DATA ON MARIJUANA TREATMENT PRESENT A DISTORTED PICTURE

Cannabis is not "50 times" stronger than in the 1970s. These estimates
are based on faulty statistics derived from samples of cannabis that
police confiscated and stored in hot evidence lockers before the THC
content was assessed. Heat destroys the THC, leading laboratories in
the 1970s to estimate that THC concentrations were around 1%. Cannabis
that is 1% THC actually has no effect, so obviously, no one would have
smoked it.

Cannabis today is probably two or three times stronger than 25 years
ago, but this increased potency does not mean people actually get any
higher or develop more dependence. In fact, some research shows that
stronger cannabis leads people to smoke less, decreasing the risk of
lung problems.

Mitchell S. Earleywine

Associate Professor

Department of Psychology

University of Southern California