An interview with Professor Joseph Boden 

Joe is the Director of the Christchurch Health and Development Study. He trained as an experimental social psychologist and worked in the US, UK, and Australia, before coming to New Zealand. He was awarded a Gold Medal for Research Excellence in 2017, and has been appointed by the Prime Minister’s Chief Science Advisor to the Expert Panel on Cannabis. ‘Make It Legal Canterbury’ were fortunate enough to score an interview with him.  

Hi Joe, thank you for sitting down to talk with us today. Recently you wrote an article on cannabis research collected as a part of the Christchurch and Dunedin Longitudinal Study. Can you tell us a bit about the findings of that research, and why it led you to support legal regulation? 

The focus of the paper was to talk about research methodology involved in longitudinal studies, to show that these results are generally more reliable. Because we collect repeated data at regular intervals, we’ve collected a great deal of data on the childhood and adolescent factors which may have affected these individuals in their life course pathways, and we’re able to use the data to build causal models of cannabis-related harm. We’ve published a number of studies about the mental health effects of cannabis use; with increased risk of depression, psychotic symptomatology, suicidal behaviour, but also cannabis dependance, and the social harms such as Amotivational syndrome where people are less likely to get a degree and more likely to experience periods of unemployment, if they’re younger and heavier users of cannabis. We wanted to convey to the public about the robustness of this research, but also to give them an idea of how much of this research has come out of a New Zealand context. 

So, despite those harms you still see legal regulation as the right step to take? Or a better way to manage those problems? 

Yes that’s correct, that’s exactly correct. All of the harms we’ve observed are in the context of cannabis being prohibited. Firstly, we’ve found that 80% of the cohort had used cannabis, so clearly the effect of the prohobition law doesn’t stop people accessing the drug. We also found that, of people who had been arrested or convicted of a cannabis offence, 95% didn’t reduce their cannabis use levels, and some actually increased use. This means that having the force of the law applied to you does not actually stop you being involved in it. Thirdly, we found that Māori cohort members were three times more likely to be arrested or convicted of a cannabis offence, which means that the law is being applied in a racially-biased way. Those three things show a law which is not fit for purpose, is not discouraging cannabis use, is not deterring people who get involved in the justice system, and we have racial bias in policing and court proceedings. Clearly this is not the approach to make. Furthermore, a barrier to treatment is the stigma surrounding the illegal nature of cannabis, which makes it difficult for people to access treatment for cannabis dependence or other related problems.  

Do you think the Cannabis Legalisation and Control Bill will address these issues, or some of these issues which have been raised in your research? 

I think it’s an excellent start. There are certainly aspects which need to be treated, but myself and a number of other public health researchers have been involved in consultation with the Ministry of Justice in the development of this Bill and much of what we’ve suggested has been put in. I think one of the key aspects of it is the R20 age. There are arguments around that age limit, but we’ve been arguing that younger use is associated with poorer outcomes, and if you’re able to control the access to cannabis for younger people, as we’ve done successfully with access to tobacco, then you’re really going to reduce a lot of these harms at the population level. 

Could you talk to us about the links between cannabis and mental illness? Will we see a big increase in mental illness, assuming the referendum passes and the law is changed? 

That’s assuming that the law change would cause more people to use cannabis and in a harmful way. I don’t think that’s true for several reasons.  We know that cannabis is not a good lifestyle-drug, meaning it’s not a thing that you can be using all the time and still carry out your daily activities without interruption. In no place in the world have we observed, where cannabis has been either decriminalised or legalised, that there has been huge increases in use. Use is relatively stable and where it does increase tends to be in older age groups with people who had used cannabis previously in life but stopped, maybe because of their work commitments or their family. When it’s legalised they feel able to do it again and remember how much they enjoyed it. This group is less vulnerable and therefore increased use is low risk. Those who are higher risk and more vulnerable are young people with developing brains that we really would want to keep away from this.  

Sure, that makes sense. What then do you think the impact of changing the law will be on our health system? 

I don’t see how there would be much of an impact at all. There may be some improved outcomes for that relatively small group of people who are regular cannabis users, because they may feel more inclined to perhaps get treatment for cannabis dependance, or they may wish to get treatment for any lung issues for example, because they feel more comfortable speaking to their doctor about it. I wouldn’t expect there to be any real increase in terms of rates of admission to psychiatric wards or any explosion of health issues. It’s worth noting that over the long period where THC content was increasing, we didn’t see a contemporaneous increase in mental health problems. 

I tend to agree with you there. I think the narrative around cannabis and the problems which people may have with it could shift quite a lot in a legal environment, where people do feel much more open about getting support if they need it. 

One of the biggest problems in this area, and with any illicit drug but particularly cannabis because it’s so commonly used, is the stigmatisation of people who use drugs for what we call recreational purposes, and I see legalising cannabis as a step toward removing that stigma.  

Much has been made about the 15% potency limit that’s a part of the Bill. Do you think the government has got the number right there? 

Roughly correct I’d say. As I understand it, this is going to be open to debate and submissions around this issue if the referendum passes, and it may be adjusted. What we would advise the Ministry of Justice, and have done, is not to revise it to be too low. For example, the allowed THC limit for government-provided cannabis in Uruguay is, I believe, 10%, which is not satisfactory for many people who like to use cannabis because that’s too weak. They’re used to a much more potent product, so, in order to satisfy the goal of taking this illicit market and not growing it, but moving it over to the licit sphere, then you have to provide them with a product which will be acceptable to them. 

Some people ask us on our Facebook page, “why does the Government want to legalise cannabis when they also want to be smoke-free by 2025?” What do you say to those people, or that point? 

Well it’s worth keeping in mind that smoke-free 2025 is an aspirational goal, and there’s never the assumption that we will be completely non-tobacco consuming by 2025 (5 years from now) and it will definitely not be the case that the government is going to be banning tobacco. What we’re trying to do is discourage the smoking of tobacco, and of course it does seem a little bit counterintuitive that we will have another product on the market to smoke, however, it doesn’t feature in the Bill at the moment but there is allowance for other products, like the vaporising of cannabis flower. Also there’s the development of edible products that will be both acceptable to the marketplace and well-developed and well-tolerated, and something that people would like to buy. Moving away from actually inhaling very hot smoke into your lungs, and trying alternative means of delivery. 

A legal market surely means better education for people around those different delivery methods and their harms as well. We don’t really talk about those at the moment do we?  

Exactly, and you see for example in the US where cannabis shops have opened and have been required to provide advice and education around these things, that this is a major aspect of this; trying to get people away from smoking, into the smoke-free side of cannabis consumption.  

What should we expect in regards to young people using cannabis if it becomes legal? 

Well, again, the goal is moving the illicit-market to the licit-market, and for example, in one year Canada managed to move half of their market from the black-market to the licit-market, and in Colorado it took about 5 years to move 80% of the market over, so it’s gradual but it means that over time you will have most suppliers of cannabis in the country being actual retail outlets where ID is required for purchase, where they won’t be serving intoxicated people, they won’t be serving alcohol or other drugs.  A much safer experience with ID means that underage people have these barriers placed in front of them. If they’re not 20-years-old it’ll be that much harder to buy cannabis. It’s worth noting, in Canada in 2018, the statistics showed that for the age group 15 to 17, about 19% reported using cannabis in that past year. For 2019 that age group dropped to 10%, which could reflect the movement of a large segment of the market into the licit sphere where they’re not allowed to buy it.  

The Bill sets a limit of 14g per day that people can buy. Do you think that that’s the right amount? 

I think it is, because it’s likely that a lot of people who are going to want access to legal cannabis live in places where they will have to drive some distance to get it. You might imagine that certain localities are not going to either have the resources to, or may decide not to have a cannabis retail outlet in their town or region or area. They’ll likely be concentrated in the major centres, plus some of the outlying centres, so you can imagine that with no mail order there’s going to be a number of people who will have to drive some distance, and would probably really only want to do that fairly infrequently, so I think it’s a good trade-off in terms of access for people who are remote. I don’t think it will be terribly abused that much in cities where people will have good access to shops, as they will here in Christchurch, because 14g is actually still quite a large amount of cannabis, and if you’re using that much in one day you should probably see your GP. 

What issues surrounding the referendum and the Bill do you think people are not really talking about. Is there anything that you would like to see discussed more in the lead up to the referendum? 

Well I think it’s really important, and the Helen Clark Foundation has emphasised this point, that, irrespective of how you feel personally about cannabis, on the 18th of September people will be using cannabis. On the 20th of September (the day after the referendum) people will be using cannabis, irrespective of what happens. It’s not about whether you think people should use cannabis, because they’re going to, irrespective of how you vote. So it’s not a vote about whether we should use it, it’s about whether we should address the reality of cannabis use. It’s here to stay, and people are going to use it. Do we give people a better alternative that keeps them out of the justice system, is safer, and will protect children?

Interview by Make It Legal Canterbury