Research shows smoking cannabis can be harmful to children, people with underlying health conditions

It's the question we're all going to be asked next year. Should smoking cannabis be decriminalised? 

Whatever's decided, health researchers have some concerns.

They are urging caution about any rush to relax our cannabis laws.

A study in Christchurch has found that cannabis is harmful to children who smoke it, and people with underlying mental health conditions.

Associate Professor Joe Boden says people who use cannabis - particularly younger people and heavier users - are less likely to obtain educational qualifications and are more likely to be unemployed for longer periods and experience dependence on a welfare benefit.

Prof Boden says there are also issues with people lighting up who have other underlying mental health conditions.

But the real concern is children.

"What we need to do is adopt a strategy that's going to discourage use amongst younger people."

Chloe Swarbrick, Green Party drug law reform spokesperson, says she does not intend for marijuana to be available for children, but that New Zealand needs to be realistic. 

"I don't want children to be able to access or to be able to purchase marijuana. But if we're real with ourselves drug dealers are currently selling these substances to younger people."

The Green Party is behind the binding referendum as part of its Confidence and Supply Agreement with the Labour Party.

Ms Swarbrick is an advocate of harm reduction, saying, drugs can cause harm but "our political, our policy and our legislative responses can either increase of decrease that harm - I want to see a decrease of that harm."

But the researchers are wondering why there's such a rush.

Prof Boden says the first step should be decriminalisation, and suggests that should happen over five years.

"Evaluate the extent to which the usage patterns of cannabis and cannabis-related problems have changed over that period and if, as I anticipate, they haven't really increased, then move to a legalisation framework."

While the whole country gets a say, it will be up to the next government to decide how quickly and if changes happen, if there's a vote to lighten up our cannabis laws.