Pubdate: Mon, 29 May 2017
Source: National Post (Canada)
Copyright: 2017 Canwest Publishing Inc.
Author: Brian Cross
Page: A8


Author cites 'toxic' effect on developing brain

The interim editor-in-chief of the Canadian Medical Association
Journal is pleading for the defeat of a federal government plan to
legalize marijuana, fearful youth will have easier access to a drug
that damages their developing brains.

"Simply put, cannabis should not be used by young people," Dr. Diane
Kelsall writes in an editorial published Monday in the journal. "It is
toxic to their cortical neuronal networks, with both functional and
structural changes seen in the brains of youth who use cannabis regularly."

Bill C- 45, if passed, would make marijuana use legal for adults aged
18 and over. Yet current research shows the brain doesn't reach
maturity until around age 25, Kelsall notes in the editorial.

A Canadian Pediatric Society position paper on the effects of cannabis
on children and youth cites such serious potential effects as:
increased presence of mental illness, including depression, anxiety
and psychosis; diminished school performance and lifetime achievement;
increased risk of tobacco smoking; impaired neurological development
and cognitive decline; and a risk of addiction.

The nine-per-cent risk of developing dependence over a lifetime
rises to 17 per cent if marijuana use started in the teen years.

"Most of us know a young person whose life was derailed because of
marijuana use," Kelsall writes. In a phone interview Friday, she said
while some young people use marijuana without problems, there are
vulnerable ones whose lives are permanently damaged. For some, it can
become a gateway to more serious drugs.

"You can end up with a bright boy or girl with promise, who's ended up
basically on the fringes of society," said Kelsall, who has dealt with
these teens in her family practice and personally.

"That is why I wrote this editorial. My worry is this legislation will
increase the likelihood that kids who are vulnerable will have easier
access to marijuana."

Bill C- 45 and associated changes to the Criminal Code would make it
possible for anyone who sells marijuana to youth to be sentenced to up
to 14 years in jail, and would introduce tougher measures for driving
under the influence.

The government has stressed its bill is meant to prevent youth from
accessing cannabis, which youth are already obtaining illegally. In
2010, Canadian youth were ranked No. 1 for cannabis use among 43
countries in Europe and North America. One-third of them had tried it
at least once by the time they reached 15.

But Kelsall said that while the government says the bill tackles the
legalization from a public health perspective, it doesn't.

The bill allows people to grow up to four plants for personal use, as
long as they're no more than one metre tall.

"If it's a public-health approach, why would you have that available
in people's homes," she asked. "What is going to happen over time is
you're going to have people with four very, very (potent) plants and
there's no way that you would know that youth aren't accessing those

She said studies looking at MRIs show definite changes in the brains
of people who smoke marijuana. The link to mental-health problems is
particularly concerning, she writes, noting that while there's no
causal link, "there is a higher risk of having these mental-health
disorders" among young people who smoke marijuana.

The Canadian Medical Association has recommended the government raise
the legal age for buying marijuana to 21, and restrict the quantity
and potency of the marijuana available to those under 25. Kelsall
called those "pragmatic recommendations" that balance the need to
protect the developing brains of young people with the reality that
young people who can't buy it legally will buy it from illegal sources.
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