A landmark study conducted in the United States and Great Britain has confirmed something many people have suspected for decades. The study reported in the London Daily Telegraph shows that people who smoke marijuana on a regular basis over a long period are putting their intelligence - their IQ -- at serious risk.


Doctors at Duke University and King’s College London tracked more than 1,000 regular marijuana smokers who were born in 1972 or 1973.  Their IQ was tested when they were 13 years old and again when they reached 38.

The results are disturbing. Researchers found that people who started smoking marijuana as teenagers had lower IQ scores as adults. They were also more likely to have attention and memory problems than others their age who abstained.

Worse, those who started as teenagers and used it heavily, but quit as adults, did not regain their full brain power. Their adult IQ scores were an average of eight points lower than they were when they were teenagers, and the damage was permanent.

This study proves conclusively that long term persistent pot smoking causes brain damage. It also proves something non-smokers have said for years:  They don't call it "dope" for nothing.