The United Nations this week reclassified cannabis by removing it from the category of most dangerous and addictive drugs, which includes heroin.

Meanwhile, a landmark study was published on cannabis and driving ability, which showed that cannabidiol (CBD), a cannabis component now widely used for medical purposes, does not impair driving.

"These findings indicate for the first time that CBD, when given without THC, does not affect a subject's ability to drive," said lead author Dr Thomas Arkell. "That's great news for those using or considering treatment using CBD-based products."

Led by the Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney and conducted at Maastricht University in the Netherlands, the study's results were published this week in the Journal of the American Medical Association.

There has been substantial growth in medical treatment using cannabis-related products in Australia and overseas. This includes increasing use of CBD-containing products for conditions such as epilepsy, anxiety, chronic pain and addictions. Many currently available products also contain a mixture of THC and CBD.