Findings of groundbreaking cannabis study released

International experts have released a study on dope smoking, based on comprehensive data from a groundbreaking Dunedin investigation.

The Dunedin cohort, which follows a large group of individuals from their births in 1972 and 73, is one of the most intensively studied in the world.

Researchers at Duke University in North Carolina have used the information to find heavy marijuana use kills brain cells - and teen dope smokers can expect their IQ to be lowered by around eight points later in life.

Quitting the drug in adulthood doesn't help.

The findings are being taken seriously by international experts, including Professor Robin Murray, from Kings College in London.

He says there are few studies on the effect of cannabis on minor psychiatric illness or on everyday life, although there are many clinical and educational anecdotal reports that cannabis users tend to be less successful in their educational achievement, marriages and occupations.

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