Stuff.co.nz 28 November 2013
Some heavy cannabis users are up to 11 times more likely to develop schizophrenia, a drug symposium in Auckland has been told.
People with a certain gene combination that exists in 25 percent of the population had that heightened risk, Otago University’s Professor Richie Poulton told the Cannabis and Health Symposium.
Risk of psychosis was elevated for those who used the drug when they were young, the Dunedin Longitudinal Study showed, but not at the levels of that gene combination.
For people who used cannabis heavily before the age of 18, the risk of schizophrenia increased by 10.3 per cent, Poulton said.
For those who used it heavily after 18 years-old, the risk increased by 4.7 per cent.
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