Pubdate: Tue, 23 Feb 2016
Source: Ottawa Citizen (CN ON)
Copyright: 2016 Postmedia Network Inc.
Contact:  http://www.ottawacitizen.com/
Details: http://www.mapinc.org/media/326
Author: Elizabeth Payne
Page: A2

POT HARMFUL TO TEEN BRAINS, FORUM TOLD

With legalization on the horizon, there is mounting evidence that
early and frequent cannabis use can have a devastating long-term
impact on teenage brains.

Researchers and officials with the Canadian Centre on Substance Abuse
held a public forum and met with staff from Ottawa Public Health on
Monday in an effort to get the message out that marijuana is not
benign, especially not for adolescents.

As marijuana moves to the front of public policy agendas in Canada and
elsewhere, CCSA officials say it is important to better understand
recent evidence about its impact on youth.

The federal Liberal government has promised to legalize and regulate
marijuana.

Because of the rapid changes in brain structure and function that
occur during adolescence, "use of cannabis during this developmental
period can have negative cognitive, mental health and physical
effects," according to a 2015 report from the CCSA called The Effects
of Cannabis use during Adolescence.

"We may be living in an environment where legalization is coming, but
let's not forget about youth whose brains are developing and are at
risk for mental health disorders," said Dr. Tony George, medical
director of the complex mental illness program at the Centre for
Addiction and Mental Health in Toronto. The Centre is calling for
strict regulation, if marijuana is legalized, to keep it out of the
hands of youth.

That could be a tough task. Canadian youth, according to 2009 research
from the World Health Organization, use cannabis more than their
counterparts in any other developed country.

Even before legalization, marijuana is the most commonly used illicit
drug among Canadian youth, many of whom consider it harmless. A 2013
drug and alcohol use survey found 22.4 per cent of youth between 15
and 19 had used cannabis in the past year, about 2 1/2 times higher
than adults 25 and older.

Teens interviewed in focus groups also reveal widely-held beliefs that
marijuana is largely harmless.

But a growing body of evidence points to serious mental and cognitive
harm for some youth who use marijuana frequently.

The earlier frequent use begins, the greater the potential for damage,
said Dr. Andra Smith, a neuroscientist and psychology professor at the
University of Ottawa.

"Earlier is worse, because the teenage brain is still developing and
it seems like cannabis is hijacking that development. That is the
problem," she said.

"If it is going to be legalized, regulation has to be key. Just
because it is legal doesn't mean it is a benign drug."

Not only is heavy marijuana use linked to impaired executive
functioning of adolescent brains, but it can change the brain's
architecture, forcing it to work harder to complete tasks.

Some research has linked teens who use cannabis at least 50 times by
age 15 with lower test scores and academic performance than those who
do not smoke.

Other research links heavy adolescent marijuana use to a higher risk
of psychosis and schizophrenia. Swedish research found that
individuals who used cannabis more than 50 times by age 18 were six
times more likely to develop schizophrenia than those who did not.

The causal relationship between marijuana and psychosis is still being
researched, but it suggests individuals with a predisposition to
schizophrenia might be more vulnerable to the psychosis-inducing
effects of THC (tetrahydrocannabinol), the active ingredient in marijuana.

Researchers are also studying links between cannabis and mood and
anxiety disorders, and other behavioural disorders.

And researchers say the detrimental effects of cannabis on driving is
also an issue of growing concern.

"The key message is marijuana is not a benign subject," said Amy
Porath-Waller, director of research and policy at the Canadian Centre
on Substance Abuse.

"There are significant effects, whether you are looking at cognitive
functioning, mental health, risk of addiction, impaired driving. The
purpose of (Monday) was to convey that message."
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MAP posted-by: Matt