T
The420Guy
Guest
The notion that heavy marijuana smokers permanently fry their brains may be
a myth.
A new Canadian study suggests there are no lasting effects on intelligence,
even among people who smoked an average of 37 joints a week for three years
in their teens.
A team of psychologists at Carleton University in Ottawa reached the
conclusion after comparing the IQ results of 70 young people -- a third of
whom were heavy users.
The findings will be published today in the Canadian Medical Association
Journal, the publication representing Canada's 50,000 doctors.
The study found IQ scores dropped while the subjects were on their smoking
sprees, but after they stopped, they quickly bounced back to the
intelligence levels of their pre-pot days. The teens had smoked an average
of 5,793 joints over 3.2 years before they were tested for their smarts.
"This lack of a negative impact among former heavy users is striking," said
Peter Fried, the Carleton psychologist who led the study.
The teens were first tested between age nine and 12. The group was
subsequently tested again during the time they were smoking pot. A third IQ
test was administered three months after they had quit smoking dope.
"One can say if they have recovered at three months, that recovery is for
real, as long as they don't start smoking again."
Worldwide, study results are split on the long-term effects of marijuana,
which an estimated 1.5 million Canadians smoke for recreational purposes.
The novel element of the Carleton study is that it compared subjects with
their own earlier IQ scores, unlike other studies that have compared dope
smokers with non-smokers.
"The controversy about whether there have been long-term effects or not is
roughly split down the middle," said Fried. "To my mind, one of the major
problems is not knowing how these folks were before they ever heard the
word marijuana."
The subjects are mainly from middle-class families in the Ottawa area. IQ
tests showed that during their heavy smoking years, they dropped an average
of four points below their IQ scores of a decade earlier. The more they
smoked, the more their results tumbled.
The Carleton researchers also waited several months to measure subjects
after they quit smoking, while other studies have dealt with tests
conducted only after a day or two of abstinence, Fried said.
But he cautioned that his study does not deal with memory or attention, so
it is not known whether his subjects will experience any long-term problems
in those areas.
A controversial Australian study published last month suggested heavy and
chronic marijuana users suffer memory loss and attention problems that can
affect their work, learning and life.
That study, from the University of New South Wales, examined 51 people who
had been using marijuana regularly. for 24 years, 51 short-term users and
33 non-users who were included as the control group.
Pubdate: Tue, 2 Apr 2002
Source: Calgary Herald (CN AB)
Copyright: 2002 Calgary Herald
Contact: letters@theherald.southam.ca
Website: Canada.Com
a myth.
A new Canadian study suggests there are no lasting effects on intelligence,
even among people who smoked an average of 37 joints a week for three years
in their teens.
A team of psychologists at Carleton University in Ottawa reached the
conclusion after comparing the IQ results of 70 young people -- a third of
whom were heavy users.
The findings will be published today in the Canadian Medical Association
Journal, the publication representing Canada's 50,000 doctors.
The study found IQ scores dropped while the subjects were on their smoking
sprees, but after they stopped, they quickly bounced back to the
intelligence levels of their pre-pot days. The teens had smoked an average
of 5,793 joints over 3.2 years before they were tested for their smarts.
"This lack of a negative impact among former heavy users is striking," said
Peter Fried, the Carleton psychologist who led the study.
The teens were first tested between age nine and 12. The group was
subsequently tested again during the time they were smoking pot. A third IQ
test was administered three months after they had quit smoking dope.
"One can say if they have recovered at three months, that recovery is for
real, as long as they don't start smoking again."
Worldwide, study results are split on the long-term effects of marijuana,
which an estimated 1.5 million Canadians smoke for recreational purposes.
The novel element of the Carleton study is that it compared subjects with
their own earlier IQ scores, unlike other studies that have compared dope
smokers with non-smokers.
"The controversy about whether there have been long-term effects or not is
roughly split down the middle," said Fried. "To my mind, one of the major
problems is not knowing how these folks were before they ever heard the
word marijuana."
The subjects are mainly from middle-class families in the Ottawa area. IQ
tests showed that during their heavy smoking years, they dropped an average
of four points below their IQ scores of a decade earlier. The more they
smoked, the more their results tumbled.
The Carleton researchers also waited several months to measure subjects
after they quit smoking, while other studies have dealt with tests
conducted only after a day or two of abstinence, Fried said.
But he cautioned that his study does not deal with memory or attention, so
it is not known whether his subjects will experience any long-term problems
in those areas.
A controversial Australian study published last month suggested heavy and
chronic marijuana users suffer memory loss and attention problems that can
affect their work, learning and life.
That study, from the University of New South Wales, examined 51 people who
had been using marijuana regularly. for 24 years, 51 short-term users and
33 non-users who were included as the control group.
Pubdate: Tue, 2 Apr 2002
Source: Calgary Herald (CN AB)
Copyright: 2002 Calgary Herald
Contact: letters@theherald.southam.ca
Website: Canada.Com
