Honourable colleagues, Amy Porath, Director of Research and Policy, Canadian Centre on Substance Use and Addiction; Dr. Sharon Levy, Medical Director, Adolescent Substance Abuse Program, Boston Children’s Hospital, and Associate Professor of Pediatrics, Harvard Medical School; Dr. Meldon Kahan, Medical Director, Substance Use Service, Women’s College Hospital; Department of Family and Community Medicine, University of Toronto; Association des médécins psychiatres du Québec. What do all these have in common? They all agree with Health Canada that human brain development continues into young adulthood to the age of 25 years old. And they all testified at Senate committees about the merits of increasing the minimum age for marijuana use to reflect this reality.

There is no denying that the adverse effects of marijuana use on the developing brain continue until 25 years of age. This is not in dispute. So why would we set the minimum age so low at 18?

Again I remind my honourable colleagues of what is supposed to be the overarching purpose of this legislation, which is protecting young people and decreasing the use of cannabis amongst our youth. How does setting the minimum age of use at 18 do that when we know beyond a doubt that the age of vulnerability continues until  25? Why do we care less about the crucial brain development that occurs in those last seven years? Why the arbitrary age of 18?

We have all heard about the negative impacts of marijuana use. Allow me to remind this chamber of just a few, keeping in mind that this legislation is legalizing the exposure of developing brains of young Canadian people to these risks.

According to the Pediatric Chairs of Canada, evidence suggests a direct link between significant mental health issues in youth who use cannabis regularly, such as dependency, psychosis and depression.

As we heard from the Canadian Paediatric Society at committee, scientific research over the last 15 years established that the human brain continues to develop into a person’s early twenties. Concerns are rising that exposure to cannabis during this important developmental period causes greater adverse effects in adolescents compared with adults, whose brains are fully developed.

According to a study published in Deutsches Ärzteblatt International, between 17 per cent and 25 per cent of teenagers who use marijuana will progress to abuse or dependence.

Users of marijuana can develop marijuana use disorder, symptoms of which include tolerance and withdrawal. Marijuana withdrawal includes irritability, anger or aggression, anxiety, depressed mood, restlessness, difficulty sleeping, decreased appetite and weight loss.

Marijuana use has been found to contribute to anxiety and depression. Evidence suggests that using marijuana during teenage years is linked to the development of mood and anxiety disorders.

In a meta-analysis conducted by the American Medical Association in 2003, evidence of mental impairments in the ability to learn and remember new information was reported in chronic cannabis smokers.

Researchers are beginning to determine how it is that marijuana causes these effects and suspect that marijuana use during developmentally sensitive periods like adolescence could be responsible for the long-lasting deficits seen in mental functioning. That’s from the Caballero K. Y. Seng Association.

That same research has established that people who begin to use marijuana in their early teens achieve poor test scores in tasks of executive brain functioning, working memory, abstract thinking and impulse control.

Then there are the physical effects.

Smoking harms your respiratory tract. Tar from a marijuana cigarette harms the lungs, and smoking it increases one’s chance of developing respiratory diseases, including lung cancer.

Smoking marijuana is known to have negative effects on cognition. Effects include difficulties with attention, problem solving and impaired judgment, decision making and ability to learn.

And what about the impaired driving and the myth among young people that marijuana impairment is different from alcohol impairment?

While the effects of marijuana are different from alcohol, it similarly impairs reaction times and the ability to concentrate on the road. When a person consumes marijuana, his or her heart rate increases, short-term memory is impaired, and attention, motor skills, reaction time and the organization of complex information are all reduced. All of these impacts are crucial for driving a motor vehicle.

Yet you really think young people whose brains are not fully developed are going to take all of this into consideration when they get behind the wheel high? They think they’re invincible at that age.

While I would like to see the minimum age set at 25, I agree with Dr. Harold Kalant, Professor Emeritus, Faculty of Medicine at the University of Toronto, who had this to say:

I think there is very little possibility of expecting that Parliament will accept an age limit of 25. All I can say is that the later it is, the better.

Dr. Sharon Levy, Medical Director, Adolescent Substance Abuse Program, Boston Children’s Hospital, and Associate Professor of Pediatrics, Harvard Medical School, said the following at committee:

. . . increase the minimum age for purchasing cannabis to 21. Age restrictions can be effective at reducing substance use by youth. Brain development continues through the mid 20s. Setting a minimum age of 21 within federal law will not only push the average age of initiation higher, but the uniform standard will also ease enforcement.

Dr. Levy did go on to say that from a medical point of view, she thinks 25 would be better. She said:

The suggestion to push the age limit higher is really one to protect the public health because the scientific data is so clear that the developing brain is really at risk from marijuana use. This age range from adolescence into early adulthood is when people become addicted to substances, particularly marijuana. The people who experience the greatest harms are those who are using in this age range. So anything you can do to delay that age of initiation is protective of the public health.

When asked about the advantage to increasing the minimum age, the committee heard the following:

The sooner we can get people to shift the top of the bell curve over to the 21 marker as opposed to the 18 or the 15, the better off we will be in the residue that will become our permanent addicts and cost us a fortune.

That’s from Glenn Barnes, Advisory Council Member, Drug Free Kids Canada.

The use of cannabis in adolescents can cause irreparable damage to their developing brains, and we cannot ignore this. Setting quantity and potency limits of cannabis to those under the age of 25 is crucial to the mental health and well-being of our youth.

That’s from Corey O’Soup, Advocate, Saskatchewan Advocate for Children and Youth.

The earlier teens start using, the greater the impact on their brain and their risk for developing substance abuse disorders later in life.

That’s from Margie Skeer, Associate Professor, Department of Public Health and Community Medicine, Tufts University.

Ms. Skeer went on to say that research has shown that:

. . . each year . . . we can delay initiation of substance use, [it] has a long-term influence on the risk of developing substance use disorders over time for young people. This is a critical juncture we are in with respect to long-term disordered use of substances, including marijuana.

I don’t want to bore you, colleagues, with my opinion, so I’m giving the opinions of experts. And finally, Dr. Philip Tibbo, Professor, Department of Psychiatry, Dalhousie University, put it quite simply when he told the committee:

. . . the CPA continues to maintain that Canadians should not be legally allowed to use cannabis until the age of 21 . . . .

The witness testimony, colleagues, from all corners of public health professionals is clear. It’s unequivocal. The higher the better when it comes to the minimum age.

I know some of my colleagues may argue that we set the age of consumption of alcohol at or about 18, depending on the province, and that we set the age for driving even lower. I’ve heard the arguments about deeming young people as adults well below the age of 25 or 21 on a host of other activities, so why should this be any different? To that, I would argue that that trend is starting to change. Only this past year, we saw in Ontario the provincial government implemented a prescription drug program that provides what it calls “young people” with free prescription drugs, at 25 and under. Clearly the Ontario government believes someone is a youth in need of special consideration well past the age of 18. They can’t be responsible for purchasing their own medication, but let’s let them use marijuana freely at any time.

At any rate, again I will say, notwithstanding my objection to legalization of marijuana altogether, in the interest of what is stated as the overarching purpose of this bill — protecting young people and decreasing usage amongst young people — I don’t see how we can’t adopt this amendment to increase the minimum age from the proposed 18 years of age to 21.

Honourable colleagues, we have an obligation to young people in this country. We have an obligation in passing government legislation and doing sober second thought, but we also have an obligation to the vulnerable. And the most vulnerable in this country, based on medical opinion and scientific opinion, are young people up until the age of 24.

If the Senate of Canada doesn’t stand up and do the right thing and protect vulnerable people, then we are not doing our job as senators responsibly on behalf of people in this country.