A new study has found that Australia and New Zealand have the highest rate of marijuana and amphetamine use in the world, while Asia boasted the lowest.

In addition, the study found that almost 3% of theAustralian population had used amphetamines, as compared to Asian use which range from 0.2% to 1.4%.

These findings come at a time when a new cannabis mouth spray is being trialled in Sydney that could have its user drug free in a short time. The drug, according to reports, is actually derived from the cannabis plant itself, and has been experimented as a pain relief medication for MS sufferers in the UK.

The study, authored by Matt Seigel of the New York Times, Louisa Degenhardt, professor at the University of New South Wales, and Wayne Hall of the University of Queensland, showed that nearly 15% of the combined 15 to 64 year old population had used marijuana in 2009.

Published in the medical journal The Lancet, the findings show that the highest users of illicit drugs are in the Oceania region.

"Cannabis use is associated with dependence and mental disorders, including psychoses, but does not seem to substantially increase mortality," the researchers said in their report.

As part of a series that The Lancet is doing on addiction, the study also revealed that an estimated 200 million people or more worldwide use illegal drugs on an annual basis, noting that between 125 million and 203 million people in the world use marijuana, between 12 million and 21 million use opioids, and between 14 million and 21 million use cocaine.

As much as 15 million and 39 million users are considered to have a drug problem, and as many as one out of 20 people between the ages of 15 and 64 use an illegal drug each year, the report said.

The research was based on information obtained from the UN Office on Drugs and Crime (UNODC), national surveys and other studies. However, it did not include an analysis on the prevalence of ecstacy, LSD, or anabolic steroid use, nor did it include prescription drug misuse.