RESEARCHERS behind a new Australasian study into the effects of cannabis use in young adults have warned policymakers they "need to be very careful" if they are considering decriminalisation.

The study, which examined the effects of Australia's most widely used drug on 14 to 19year-olds up until the age of 30, found there was a "very strong" association between cannabis use over time and harmful outcomes.

According to the latest figures from the National Drug Strategy Household Survey, in Australia 1 per cent of all 14 to 19-year-olds use cannabis daily, while 4 per cent use it weekly.

[continues 180 words]