Health Committee on May 13th, 2014

[Philippe Lucas]

As you say, through the MMPR there are ratings now of THC and CBD on cannabis strains. For years, we didn't have access to that. What patients have been doing for years and frankly for generations is they've been using self-titration, which is basically starting at a low dose and working up until they find a therapeutic window that's effective for them. It gives them therapeutic relief without feeling a level of discomfort.

The nice thing is, compared to even aspirin and certainly more potentially dangerous pharmaceutical drugs like opiates, there's a very low risk of people coming into problematic use. For example, you can't die from using too much cannabis. There's no way to overdose. The actual risk of people self-titrating is very minimal in terms of personal risk. Once people figure out the right dose for themselves, it tends to be very consistent as they work across different conditions.

Do you have anything to add to that, Dr. Walsh?

[David Wilks, Conservative, Kootenay—Columbia, BC]

I want to just interject, if I may. Last week, we had Dr. Harold Kalant here from the University of Toronto, who both of you probably know. He said the following:

There is no such thing as a harmless drug. Everything with pharmacological action has the ability to produce harm, depending on the amount used, how often, for how long, by whom, and under what circumstances. Not surprisingly, the harmful effects of marijuana are most often found in heavier users and those with greater vulnerability.

Among those who begin to use marijuana as adults, the most common adverse effects include chronic inflammatory changes in the respiratory system, poor memory, poor work performance in activities requiring mental and physical skills, driving accidents, and addiction. The physical and mental effects usually recover on cessation of use.

But he went on to say:

...adolescents and young adult users of marijuana greatly outnumber mature adult users. Young beginners, those who begin use as early as 12 or 13 years, are much more vulnerable to harmful effects....

I want you to talk about that for a bit. We've talked about the medical use, but let's talk about the adolescents and the youth who come into this at age 12 or 13. How do we deal with them? How do we convince them that this is not to be used as a recreational drug as opposed to what you two are talking about with regard to the medical use? There are far different reaches there.

[Dr. Zach Walsh]

Well, I think you make a good point. As a former junior high school teacher, that's certainly something I consider a lot. How do we minimize the risks for vulnerable young people?

I think we can look at the model that we've used for tobacco, where we have really, through accurate and aggressive information campaigns, been able to reduce the uptake of tobacco rather successfully amongst young people. That's a major public health victory that we've been able to have.

One of the reasons we see some use amongst young people is that there's a lack of trust in the information they're provided because of a long history of stigmatization and exaggeration in the war on drugs. We end up with young people who don't believe what they're told and won't take the advice of older people.

You're right, there is nothing that is harmless. So we want to think about relative harms and risks relative to other substances. Through accurate education, public health initiatives, and prevention, we can be effective at protecting those young people, which I think is a priority.

[The Vice-Chair, NDP, Libby Davies]

Thank you.

We've gone over time. We'll come back and I'm sure there will be another question.

I just want to say that our Liberal member has been unavoidably detained. I'm sure she'll be showing up later, so we'll now go to Mr. Young.

[Terence Young, Conservative, Oakville, ON]

Thank you, Madam Chair.

Mr. Walsh, do you have any medical training? Are you a pharmacist or a doctor?

[Dr. Zach Walsh]

I'm a registered clinical psychologist. I took medical neuroscience courses.

[Terence Young, Conservative, Oakville, ON]

The answer is “no”, right?

[Dr. Zach Walsh]

So, yes.

[Terence Young, Conservative, Oakville, ON]

The answer is “no”, and you're not a doctor or a pharmacist.

[Dr. Zach Walsh]

I am not a doctor or a pharmacist, no. A health care professional....

[Terence Young, Conservative, Oakville, ON]

Okay.

You said that there is an “absence of evidence for...health risks and harms associated with cannabis use.” I want to try to get this quote right.

Is that right?

[Dr. Zach Walsh]

Yes.

[Terence Young, Conservative, Oakville, ON]

Okay, well I want to tell you what we've heard at this committee.

We've heard from a Ph.D. in pharmacology from U of T, and we've heard from a director of patient care related to addiction at Women's College Hospital, and others that marijuana interferes with the prefrontal cortex of the brain, which is responsible for memory, judgment, and decision-making, effects that last for up to a month but with young people may cause permanent damage.

We've heard from another expert from the Centre for Addiction and Mental Health at a leading Canadian hospital that marijuana use can cause psychosis and schizophrenia in some people, and that users are twice as likely to be involved in a vehicular accident.

We've also heard from experts that there are links to various cancers, and that smoking anything is adverse to one's health.

That is just some of what we've heard on this committee, so I want to ask you how you can possibly claim that there is no evidence of health risks and harms?

[Dr. Zach Walsh]

I think I mentioned some of the risks in the rest of my testimony, the ones you mentioned regarding psychosis.

I think we're talking about relative health risks and I was speaking specifically about long-term physical consequences when I talked about a relative absence and quoted the DEA administrative....

[Terence Young, Conservative, Oakville, ON]

Thank you.

You suggested, or seemed to be suggesting, that people addicted to cigarettes should switch to marijuana because marijuana use actually helps them with their addiction to nicotine. Is that correct?

[Dr. Zach Walsh]

I think you are referring to Philippe.

[Terence Young, Conservative, Oakville, ON]

Oh, I'm sorry, I beg your pardon, Philippe.

[Philippe Lucas]

Yes, the suggestion is that cannabis users can actually cut down or quit—

[Terence Young, Conservative, Oakville, ON]

Is that what you would recommend to people who are addicted to nicotine, that they switch to marijuana?

[Philippe Lucas]

I think that from a net harm-benefit ratio they'd have better health outcomes using cannabis than they would nicotine.

[Terence Young, Conservative, Oakville, ON]

What about a third option of no addiction at all?

[Philippe Lucas]

That would be ideal and wonderful, but I think that in society and in our world we realize that before people can take those steps that would perhaps be preferable to some or to society as a whole, sometimes they need harm reduction in order to be able to get to that point.

[Terence Young, Conservative, Oakville, ON]

Thank you.

Mr. Walsh, you said there is literature somewhere, or that you agree, that marijuana can cause anxiety. But you also claim that it can also relieve anxiety, and that panic attacks are most common for naive users. Does that mean new users or people who aren't addicted?

[Dr. Zach Walsh]

Yes.

[Terence Young, Conservative, Oakville, ON]

I'd like to suggest to you that we heard from the experts that panic attacks are relatively common and that anxiety is also an effect of withdrawal from marijuana. So marijuana can decrease your anxiety until the user stops.

I don't understand why you made that statement. While it can relieve anxiety, which is great until it stops....