Smoking weed daily as a teen reduces probability of high school completion by 60%
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A new study has shown that children under 17 years of age who smoke marijuana daily are over 60 per cent less likely to complete high school than those who never smoke weed at all.

The same children are also 60 per cent less likely to graduate from university and seven times more likely to attempt suicide.

Australian scientists working with the Cannabis Cohorts Research Consortium published their research this month in The Lancet.

Study co-author Edmund Sillins told The Washington Post reporter Christopher Ingraham that even low-level cannabis use resulted in significant negative outcomes in the study, suggesting that there is no safe level of cannabis use for teenagers. 

Cannabis use was associated with lower odds of high-school completion and university degree attainment, and substantially increased odds of later cannabis dependence, use of other illicit drugs, and suicide attempt.

The research analysed data from three large, long-running studies from Australia and New Zealand, which included over 2,500 individuals under the age of 17.

The researchers said their study showed, "clear and consistent associations between frequency of cannabis use during adolescence and most young adult outcomes investigated, even after controlling for 53 potential confounding factors including age, sex, ethnicity, socioeconomic status, use of other drugs, and mental illness," as reported by The Washington Post. 

The study concluded that preventing the use of cannabis by teenagers would have health benefits and that any effort to legalise the drug should carefully consider the effects on this age group. 

However, as Ingraham from The Washington Post reports, "First, the causality isn't 100 per cent clear. The researchers did a fantastic job of trying to account for a number of confounding factors. But particularly when it comes to the educational outcomes, there are a lot of factors at play. For instance, if a teacher knows or even suspects that a certain kid is using drugs, that may predispose the teacher against that student."