NOT EVERYONE'S HIGH ON POT'S RISING STATUS

Young Brains Can't Handle Today's Powerful Weed, Psychiatrist Warns

Cannabis has gone mainstream in a big way since the era of Reefer
Madness, the unintentionally funny 1936 B-flick that became a cult
hit in the 1970's for its hysterical warnings that smoking pot will
lead to manslaughter, murder, rape, suicide or, at best, eternal insanity.

Boomer-age politicians generally admit to having at least tried it --
if with questionable candor in the case of former U.S. president Bill
Clinton, who claimed he didn't actually inhale -- and marijuana's
cultural influences are everywhere, in music, art, film and on
prime-time TV, where its starring role in the retro sitcom That 70's
Show barely raised an eyebrow.

In Canada, it's now legally prescribed for medical uses, including to
counter nausea and weight loss from chemotherapy. The federal
Liberals under former Prime Minister Jean Chrtien even mused about
decriminalization, as politicians have periodically done since the
1972 Le Dain Commission recommended relaxing what is apparently one
of the country's most-flouted laws.

Though Prime Minister Stephen Harper's Conservative government put a
quick damper on any such laissez-faire thoughts, the proverbial genie
is way out of the bong: an estimated one in six Canadians between the
ages of 15 and 64 smoke marijuana, according to one recent United
Nations study.

Suzanne Archie makes it clear she's not a pot prude, particularly
when it comes to moderate use by adults -- which she defines as once
or twice a month.

She also acknowledges pot has some benefits at low levels, like
lessening anxiety, and "can't say I haven't tried it."

But the psychiatrist at St. Joseph's Healthcare is concerned that
early use is potentially creating a ticking time bomb for those who
are already at risk of developing mental illness.

Today's weed is not only way stronger than the stuff her generation
smoked in the Sixties and Seventies -- THC, the active ingredient, is
now as high as 15 per cent, compared to one to five per cent back
then -- but kids are puffing it at a much younger age, she said.

Whereas boomers typically began regular use between 19 and 24 -- that
is smoking it perhaps once a week -- the age range has dropped to 15
to 20, and sometimes younger.

A 2004 Canadian study, for instance, found a quarter of 14-year-olds
smoke pot -- a figure Dr. Archie believes is now higher.

As with binge drinking, early cannabis use is a particular concern
for those vulnerable to her area of expertise -- psychosis, which is
"a disturbance in understanding reality," like hearing noises that
aren't there or perceiving neutral behaviour as threatening --
because the brain is still developing.

"We don't fully understand how much is going on during those teenage
years with all those hormonal changes," Dr. Archie told a recent
public forum on the relationship between marijuana and psychosis.

"There are lots and lots of changes in the brain, and that's when
people are actually vulnerable to developing mental illness. It's not
really when people are 30, it's actually from puberty to about age
25, when all this brain development is going on," she said.

"When you're 15, your brain is making all these circuits all over the
place. This is why teenagers are impossible, because their frontal
lobes are connecting to the emotional centres in the brain, and you
know what the emotions are like in a teenager.

"And this is all new growth. We didn't know that 10 years ago. We
thought their brains were just smaller versions of adult brains."

What doctors also didn't realize until more recently, Dr. Archie
said, is that humans are hard wired for pot: the brain has special
receptors that are specifically designed to process it.

This is because our bodies naturally produce low levels of cannabis,
which becomes particularly active for women during childbirth.

"We are supposed to experience a certain amount of cannabis and
that's why we have cannabis receptors in the brain," Dr. Archie said.

"It makes perfect sense because it is an analgesic and it helps you
to forget about pain," she said, adding with a laugh. "It's probably
helped mankind to continue because women forget. Think about it, you
completely forget about how painful childbirth was, because otherwise
you wouldn't be having (more) children."

While this may or may not help explain why men can never remember to
put down the toilet seat, the hardwiring has a darker side in people
with a genetic vulnerability to mental illness.

Dr. Archie said people with a predisposition toward schizophrenia,
for instance, have a higher number of cannabis receptors in their
brain, making them more prone to addiction.Pot disrupts their brain's
dopamine levels and causes hallucinations, she said. Studies suggest
early use is also a problem for teens with a genetic vulnerability to
psychosis.

She cites a long-term New Zealand study that tracked 1,000 children
as they grew up. It found those who smoked pot once or twice per week
between the ages of 13 to 15 were nearly four times more likely to
experience psychosis, compared to those who did not.

Even when a family history was factored out, the pot smokers were
still twice as susceptible.

But another study found regular pot use played a negligible role in
psychosis for younger teens who had no genetic risk.

Yet it did show that those at high risk were significantly more
likely to report hallucinations in their mid-twenties -- or 10 years
after their regular use.

"It's really that teenage use that's problematic," said Dr. Archie,
who advises those who want to indulge in pot or alcohol to hold off
until they're 19.

"I think what people need to hear is that it's not safe for
adolescents to be using this stuff, that their brains cannot handle
it and that toxic levels of this stuff, just weekly use, creates
psychiatric problems down the road," she said.

"It's kind of like trying to prove cigarette smoking causes cancer
back in the Fifties. That's really the level where we're at now."