New research, which is about to be published in The Lancet, has found Australians and New Zealanders have among the highest levels of marijuana and amphetamine use in the world.
The study by Professor Wayne Hall of the University of Queensland found that up to 15% of people in the Oceania region have used marijuana in the past year and up to 3% have used amphetamines.
Prof Hall says he's not surprised by the result as cannabis is a large part of youth culture in both countries.
He says other hard drugs, such as cocaine and heroin, are not so popular in New Zealand - which may be why amphetamine use is slightly higher than other places.
