New Zealand's traditional hard line on cannabis could soon be eased, says a leading academic who predicts a "sea change" is imminent.

His comments follow a profound change in how the drug, also known as marijuana and dope, is being treated overseas.

And an alcohol and drug counsellor says New Zealand is in the "stone age" when it comes to marijuana laws and that alcohol is actually the most dangerous substance in the country.

Waikato University academic Bill Cochrane, an associate researcher at the National Institute of Demographic and Economic Analysis, said a change in the way people perceived marijuana use and users could be coming, and a review of New Zealand's cannabis legislation was long overdue.

But Waikato Times subscribers polled are dead against any decriminalisation of the drug - with 67 per cent of 405 people saying they would not want the drug legalised.

But the group who want to see it legalised (17.8 per cent) and the group who might want to (13.1) are growing.

The majority of those surveyed in the past three days were over 50 years of age - 60 per cent - so the Times also asked readers of waikatotimes.co.nz what they thought, with the results the polar opposite. Of the 664 people who responded, 65.8 per cent wanted cannabis decriminalised, while 31.8 per cent were against it.

Laws regarding recreational cannabis use in some parts of the United States and Uruguay have recently been overhauled, which has stimulated debate in other parts of the world - including this country - over policing the drug.

Green Party co-leader Metiria Turei recently reaffirmed that decriminalisation of cannabis remained one of her party's policies, and would be on the table for negotiation in any post-election talks with the Labour Party, but was not a major issue to "fight to the death over".

Dr Cochrane said he believed the "net increase" in social harm from decriminalising cannabis would be minimal. "If people want to get themselves marijuana, they are able to do so with ease. For example I live in Hillcrest and there are at least a couple of tinnie houses in walking distance - so decriminalisation would make it only marginally more available than what it is now.

"Also, a lot of people have been pushed into criminal organisations they might not have otherwise been involved with."

Alcohol and Drug Assessment and Counselling clinical manager Roger Brooking said it was "high time" the Government read some of the research and came to its senses about decriminalising cannabis.

"I think New Zealand is still in the stone age on this one."

Mr Brooking said synthetic cannabinoids appeared to be more addictive and dangerous than the real thing, and alcohol was still the biggest problem.

However, he said marijuana could be addictive and interfered with brain development and learning in younger users.

Decriminalising cannabis could free up time and money in the justice system for more serious crimes, he said.

The Law Commission conducted a review of cannabis legislation in 2011 and although it did not go as far as recommending decriminalisation, the review indicated a need to revisit the legislation "in quite a major way".

The Waikato District Health Board did not repsond to requests for comment on the drug's health effects by deadline. mike.mather@waikatotimes.co.nz

See: Fears for CBD spur opposition to legal highs, A8