THE head of Australia's leading alcohol research body has called for marijuana to be legalised to reduce the harm of drinking.

Robin Room, director of the Centre for Alcohol Policy Research, says marijuana should be legalised under strict controls because the social harm associated with it was significantly less than from drinking.

"It makes sense to legalise marijuana in a controlled market," he told the Herald Sun yesterday. "We are in a situation where we need to look ahead. I think we need to have the discussion and it makes a lot of sense in terms of, among others, cutting down government costs to have a fairly highly controlled legal (cannabis) market and, while we are at it, tighten up the legal market of alcohol in the same way we tightened up the market of tobacco."

Prof Room, a leading academic at Melbourne University, is funded by the Department of Human Services.

In an ideal world, Prof Room said teens would not smoke marijuana or drink alcohol to excess.

But if an 18-year-old was going to use substances, he said they would likely land themselves in less trouble after using cannabis rather than bingeing on alcohol.

Teens were "better off" on a mixture of booze and marijuana rather than just pure alcohol in social settings, he added. Alcohol was more dangerous than cannabis because it had a closer association with aggression and violence, loss of co-ordination and impacts on work and family life, he said.

"Cannabis is not without harm but it's substantially less than alcohol and tobacco in terms of social harm," he said.

"If you are adding the cannabis to an equal amount of alcohol, then in some ways you'd be probably less likely to be aggressive but it's a bad idea to add it on if you want to drive a car."

Prof Room said if marijuana were legalised, among the measures to control the use should be "state sellers" and "state stores" where sales were regulated. It should not be sold in supermarkets nor advertised on TV or at sporting matches.

While Prof Room acknowledged many people would be "surprised" and even "bothered" by his stance, the statistics backed him up.

The controversial proposal comes as Melbourne continues to battle booze-fuelled violence, and alcohol-related hospital admissions soar for men and women.

aleks.devic@news.com.au