August 27, 2012–A new study reinforces the need to protect adolescents from a commercial marijuana industry that will come after them, like the tobacco and alcohol industries do, if marijuana is legalized.
The study, reported today by the Associated Press, involved more than 1,000 people in New Zealand who were interviewed and tested several times, beginning at age 13 and ending at age 38. Those who used marijuana persistently by age 18 experienced an average IQ drop of 8 points at age 38. Reducing use or quitting did not fully restore the drop in IQ. Those using marijuana frequently after age 18 did not experience a drop in IQ.
The study was published online today by the Proceedings of the National Academy of Sciences.