Health Committee on May 27th, 2014

[Dr. Didier Jutras-Aswad]

Yes, there are data. As I said, actually, it is quite clear, as Dr. Wood mentioned in some way.... The data for now shows that in general and for the general population the risk associated with cannabis actually is relatively minor in some ways, when someone is not vulnerable, but there are clearly some factors that would put people more at risk. As I mentioned, there's genetics, but clearly the age and youth....

One of the data we have now is about the cumulative consequences of exposure to cannabis. One of the factors that will actually increase the risk of having cognitive problems associated with cannabis is the age of exposure. Some studies that have been conducted are basically saying that when the exposure occurs before 15 or 16 years of age, the effect on cognition can be much more important and much more long term than when the exposure occurs at an older age, let's say, or in adulthood, for example.

[Eve Adams, Conservative, Mississauga—Brampton South, ON]

Would it surprise you that, according to the study, the average age at which someone first tries cannabis is 15.6 years? You're saying that this is a critical period of time. This is the average, which means that many more people try it at a later age, but many people try it at a much younger age. Is that of concern to you?

[Dr. Didier Jutras-Aswad]

There are two things. Is it surprising? Not really. We know that cannabis is among the first substances used when someone starts using drugs, with tobacco and also alcohol. We know that cannabis will be one of the first drugs used by youth in general. We also know that the peak from an epidemiological standpoint, although I'm not an epidemiologist, is indeed during adolescence or early adulthood; so it's not very surprising.

Is it of concern? As I said, the younger the exposure the more likely someone is to have long-term consequences from cannabis exposure. Obviously, if that peak occurs later in life during adulthood when the brain is well developed, more solid, and less flexible, we might think that the burden associated with cannabis exposure might decrease.

Yes, it is concerning that it occurs at a young age, rather than exposure occurring later.

[Eve Adams, Conservative, Mississauga—Brampton South, ON]

Finally, let me turn to pregnant women. Currently, possession is obviously not legal. If it were readily available in variety stores.... I think we've all been concerned, when we see women drinking or smoking when they are pregnant. There are a number of studies now showing that there are some significant impacts on the infant.

Can you speak to those impacts, please?

[Dr. Didier Jutras-Aswad]

We have much better data on the impact of exposure during pregnancy for alcohol and tobacco, for sure, but we have emerging data for the impact of cannabis exposure.

I have to say, though, that all the research in that area is very difficult to conduct, just for ethical reasons. Obviously you cannot expose a woman and do a controlled placebo study, but the data we have now—from the human study from Brain Bank, for example, but also from animal models—show that cannabis can have some impact on brain development for the fetus and also in the long term. Obviously, as I said, the younger the exposure, including during the fetal life, the more important the long-term consequences can be.

Again, that research field is at its beginning, and it's a very difficult one to study for ethical reasons.

[Eve Adams, Conservative, Mississauga—Brampton South, ON]

I imagine it would require self-disclosure.

[Dr. Didier Jutras-Aswad]

Yes. We can talk about it for a long time, but obviously disclosure is a main problem for the validity and quality of the information reported by women saying whether or not they have used cannabis. It's a huge problem to conduct a really good study in that field.

[The Chair, Conservative, Ben Lobb]

Ms. Bennett, you're up for seven minutes, please.

[Carolyn Bennett, Liberal, St. Paul's, ON]

Thank you all.

I'm afraid that our track record at parliamentary committees, with this government being able to use its majority to put in recommendations and even confine studies such as this in a narrow way and then replace what was heard with what they have already predetermined would be the recommendations of a committee hearing, means that I would prefer to use my time, particularly with Dr. Wood and Dr. Jutras-Aswad, for you to make very clear what, if you were writing the report for this committee, the recommendation would be.

We've heard from Dr. Wood that free and easy access under prohibition is not a good thing. The Canadian Public Health Association has recommended an approach with taxation and regulation. We've heard that there needs to be more research, and more research around even the kind of research we're doing on personalized medicine, genetic predisposition. I'm afraid I'm old enough that, as a physician in the emergency department at the Wellesley Hospital in Toronto, we saw people having psychotic breaks from having seen The Exorcist, because they were predisposed in some way.

I would like to give you both the time to tell us, if you were writing the recommendations for this committee around this study and the broader study that we wished it were, what those recommendations would be, so that the people of Canada will know what this committee heard when they see the weak recommendations that will come out because this Conservative majority continues to use its majority to replace what was heard from the witnesses.

It is very important that you tell us now what needs to be in this committee report.

[Dr. Evan Wood]

Just listening to the conversations this morning and watching the debate in society around this issue, I think the biggest challenge for people, including members of the committee whose comments this morning reflected concerns for adolescents, for unborn children, and drug-impaired driving, is that, while all of these concerns are valid, in my opinion, they are worsened by prohibition. All the organized crime, grow ops, home invasions, and fires where these grow ops exist are all a natural consequence of prohibition in the same way that all the organized crime, corruption, and violence emerged under alcohol prohibition.

For people who are sincerely concerned about young people, fetuses, and all of the harms to our society from this massive unregulated cannabis industry, I just encourage them to pause, take a deep breath, and acknowledge the fact that cannabis is more freely and easily available to young people than alcohol and tobacco are, and that, if we strictly and with a great deal of government intervention, regulated the adult use of cannabis, we could probably address many of these harms and at the same time do away with the forbidden fruit phenomena that is also a natural consequence of prohibition with young people wanting to use cannabis because we've made it illegal.

The policy has been a failure. It's been an extreme burden to taxpayers. It has been a taxpayer investment that has resulted in the growth of organized crime. It simply has not worked, and we shouldn't continue to pour money into this failed exercise.

We should be having a thoughtful conversation about taxing and regulating the adult use of cannabis as a strategy to address all of these harms that we've been dealing with for a long time. It's going to take a lot of courage for any government to do this, but I certainly encourage our current government to approach this in a thoughtful way and look to be innovative instead of making the same mistakes that we've made in the past.

[Dr. Didier Jutras-Aswad]

I go back to what I said earlier that, in general—and in general is very important—cannabis is rarely harmful, but there are some specific people for whom cannabis may be harmful, and there's also a very specific aspect of cannabis, including the ratio of THC and CBD, that should be taken into account.

That being said, obviously there will always be people who use cannabis. If we want to decrease the burden associated with cannabis use, we have to be able to protect those who are vulnerable, but also be able to control what is in the substance and be able to actually make sure the messages sent to society in general are accurate, but also can be said clearly.

The question is how we could regulate to protect vulnerable people to make sure that...for the general population for which cannabis is not harmful, it would not necessarily prevent them from doing something that is harmful, but how we could protect those people and control what is in the substance. That question is obviously outside of my specific knowledge. What I can say from a clinical standpoint is that regulating and controlling what is in the substance is obviously not something that is done by drug dealers who sell the drug on the street, and it is not done by criminal organizations that would actually put the cannabis on the market. That's very clear to me.

The second point is for me to be able to conduct more accurate research on the specific effect of the different chemicals that can be found in cannabis. Also a very important thing for me is to differentiate therapeutic use from the law and regulations regarding cannabis use for recreational purposes.

Those are two very different reasons and topics which, in my opinion, are sometimes mixed together in the population, but also among politicians and even scientists.

[Carolyn Bennett, Liberal, St. Paul's, ON]

People do see cannabis as their medicine for very serious medical conditions, such as MS in a lot of my patients. Therefore, you'd think that, in personalized medicine in the future of health and health care in Canada, research on personalized medicine, including THC and cannabinoids, is important.

[Dr. Didier Jutras-Aswad]

As for therapeutic use, I think more research is needed. If you were to use a compound as a medication, then just as for any other kind of medication, you have to know as a scientist but also as a doctor what is in that medication. Sorry to use this as an example, but if I had a bag full of pills, not knowing what is in those pills, I would not give any to one of my patients.

To be able to use something for medical use, you have to know what's in it. The regulation does not allow for that when using cannabis for therapeutic purposes.

[The Chair, Conservative, Ben Lobb]

Thank you very much, Ms. Bennett. Your time is up.

Now we're going to Mr. Lunney, for seven minutes.

[James Lunney, Conservative, Nanaimo—Alberni, BC]

Thank you to all of the witnesses for contributing today.

Way out there in Halifax, is it Dr. Asbridge? Is it doctor or mister?

[Mark Asbridge]

I'm in Toronto, actually, and it's mister.

[James Lunney, Conservative, Nanaimo—Alberni, BC]

Oh, you're in Toronto.

Mr. Asbridge, you mentioned in one of your comments about a study that showed 6% tested for THC in B.C. I think you were referring to a roadside test. Were those accidents that you were referring to? How was that test done? Was it saliva, urine, or blood? Could you clarify that for me, please?

[Mark Asbridge]

Yes. That was the B.C. roadside survey. There have been a couple of iterations of that. This was the 2010 version. It was random stops at the roadside. These were not drivers in crashes. It was determined with an oral fluid sample.

[James Lunney, Conservative, Nanaimo—Alberni, BC]

I think you said there were problems with reliability.

[Mark Asbridge]

A little bit, small problems.... It generally is pretty good but there are some false positives and false negatives, as with most tests.

[James Lunney, Conservative, Nanaimo—Alberni, BC]

Impaired driving is certainly a concern in terms of public safety. There's compelling evidence that in Colorado there are a lot of accidents related to marijuana use and hospitalizations related to these crashes have been going up. I just want to leave that for a minute and go in another direction.

I want to go back to Dr. Jutras-Aswad. Well, I go back to Dr. Kalant from University of Toronto who spoke here. He's a professor of pharmacology. He particularly emphasized the fact that those who start young have the greatest impairment, the risk of depression later, risk of motor vehicle accidents.

We had other evidence, in fact, of impairment in cognitive development, from functional MRI, that in fact there's delayed myelination in the frontal areas, where higher executive functions are developing, where reasoning, problem solving, decision-making...areas that can affect adolescents later in life...even maternal smoking has an impact; it's measurable later in life.

In your review of some 120 studies that looked at different aspects of the relationship between cannabis and the adolescent brain.... That is a concern to a lot of us here because it seems they're starting young. They may be choosing their career path unwittingly at a very young age because they're going to impair their ability to do higher executive functions with their brain that would require greater cognitive engagement.

You talked about the association between cannabis and subsequent addiction to heavy drugs and between cannabis and psychosis. I would like you to expand a little bit on that because your time was limited earlier.

[Dr. Didier Jutras-Aswad]

There are obviously two different questions here. One is the relation between cannabis and subsequent addiction to other substances, which is also known as the gateway theory, which has been studied and reported on for a number of years. It basically says that a lot of studies have shown that a vast majority of people will go on to use cocaine, heroin, or what are called hard drugs. When you look back at their story of substance use, they started by using cannabis, or quite often cannabis will be on the path of using other drugs. That has led to this idea that maybe cannabis was leading to other addictions that obviously as for all or most other outcomes what has been shown actually.... It's pretty much a similar story to psychosis. Indeed there is some data showing that cannabis may have some impact on how the brain will develop that could put someone at an increased risk of developing an addiction.

Obviously there are other much more important factors involved in developing addiction to other drugs.

The other thing we have to take into account goes back to what I was saying, that, in general, cannabis is not related to long-term harmful consequences. Most people or even most adolescents who use cannabis will not go on to use harder drugs. From epidemiological data, we know there's a minority of people who will go on to use other harder drugs, but still, cannabis is along the way. We know there is some neurobiological effect of early cannabis exposure that could increase in some ways the risk of developing other addictions.

As for psychosis, and again to put it briefly, what is known now is that cannabis per se is probably not itself a cause of schizophrenia or of long-term psychotic disorders. What we know now is that cannabis can act as a stressor or as a trigger for people who have a vulnerability with respect to psychosis; when exposed to cannabis, they will go on to develop schizophrenia, for example.

[James Lunney, Conservative, Nanaimo—Alberni, BC]

You talked about the areas of the brain affected by cannabinoids and by cannabis; areas that govern our learning and the management of rewards and motivate behaviour, that are engaged in those functions of decision-making, habit formation, and motor function. Those things are developing in adolescence. When we talk about a genetic expression, I mean, genes are turned on and off by external factors in many cases.

Are you aware of the impact of maternal smoking or picking it up in the home—there's a lot of talk about second-hand smoke in other capacities—where there's marijuana in use and the kids are growing up in that environment? In your research, are you aware of any connections between maternal smoking or environment affecting the kids growing up in that environment?

[Dr. Didier Jutras-Aswad]

I would not be able to comment on that from a scientific perspective, other than on fetal exposure to cannabis through maternal smoking, as I responded earlier.

[James Lunney, Conservative, Nanaimo—Alberni, BC]

Dr. Jutras-Aswad, you talked about the medical use. This study is not about medical marijuana, per se, but the other factors in marijuana. Because of this perception that marijuana is harmless and well tolerated, it hasn't adequately been studied in terms of the full range of compounds in marijuana and the impacts they have. I think you made that remark to Dr. Bennett about an unknown quantity there, the mixtures, the numbers, the potency of marijuana.

To go back to the Le Dain commission, I guess it was, the potencies way back in that era 20 years ago were 1%, maybe 2%. Currently, they’re at 10% to 15%, and some are as high as.... Where I'm from on Vancouver Island, we have Lasqueti Gold out there. Somebody referred to the widespread production of marijuana in British Columbia. Some of that is very high potency, even up to 30%. At least we've heard evidence that it can be as high as 30% in some productions. We're talking about something that has a hugely different impact from what earlier generations experienced.

Can you comment on that aspect, of the range?