NEW ZEALAND HERALD (New Zealand), BBC NEWS (UK)
AUCKLAND- Pot smokers themselves are eternally divided over whether taking a toke or two makes them dumber or smarter. But a New Zealand study, just released after two decades of research, found that the persistent use of marijuana before age 18 can cause lasting harm to intelligence, reports The New Zealand Herald.
Researchers found that those who started smoking cannabis in their early teens - while their brains were still developing – wound up with a lower IQ.
For more than 20 years, researchers have been tracking a group of people from Dunedin, a medium-sized New Zealand city.
The subjects were assessed as children - before any had started using cannabis - and then re-interviewed repeatedly, up to the age of 38, reports BBC News.
The findings show that the more people smoked pot, the lower their IQ got, especially among those who started using cannabis at an early age.
Commentators, some with personal experience, chimed in on the New Zealand Herald website:
The study finds that stopping or reducing cannabis consumption fails to fully restore the lost IQ.
One wise-guy Kiwi tweeter took the findings as a chance for a cheap shot at Dunedin, a major student town on the South Island of New Zealand.
Clarification about research "Smoking pot lowers your IQ" research. --> Just if you live in Dunedin in New Zealand.j7.r2.ly— Rex Hammock (@R) Août 27, 2012