Pubdate: Mon, 21 Nov 2005
Source: Australian, The (Australia)
Copyright: 2005sThe Australian
Contact: http://www.theaustralian.news.com.au/files/aus_letters.htm
Website: http://www.theaustralian.com.au/
Details: http://www.mapinc.org/media/35
Author: Simon Kearney
Bookmark: http://www.mapinc.org/pot.htm (Cannabis)

CANNABIS IS WORST DRUG FOR PSYCHOSIS

FOUR out of five people with incurable schizophrenia smoked cannabis
regularly between the ages of 12 and 21.

Andrew Campbell, of the NSW Mental Health Review Tribunal, warned that
a hidden epidemic of cannabis-induced psychosis could make the
so-called soft drug more dangerous than heroin.

"It's much safer to take heroin -- you can live to be 90 with heroin,"
Dr Campbell said.

A five-year review of the histories of mentally ill patients in NSW
who had been committed to an institution or needed compulsory
treatment found four out of five had smoked marijuana regularly in
adolescence.

"That's 75 to 80 per cent of the people who are getting long-term
psychotic disorders who are not getting better," Dr Campbell said.
"That's four out of five who were healthy, they could smoke, they were
not sensitive to the stuff, then they hit the wall.

"It can take up to five or six years. It's an epidemic, and in some
ways we're blind to it."

Dr Campbell has kept records of his work reviewing the histories of
these incurable patients and believes the results show the need for a
national campaign about the health problems and dangers associated
with the teenage use of marijuana.

"If you can just keep the kids off cannabis until they're 21 and
they've got the keys to the door," he said.

"There seems to be a vulnerable period at critical adolescence. Give
it to an adult -- people still get stoned, but you get over it."

Monash University psychiatry professor Paul Mullen told The Australian
there were several overseas studies that backed Dr Campbell's findings.

In particular, a Swedish study had shown young men joining the army
were more likely to suffer from schizophrenia in later life if they
had smoked cannabis regularly in adolescence.

Professor Mullen said scientists knew the early stages of
schizophrenia caused people to be more likely to take drugs at a young
age, but researchers had so far not been able to prove the drug abuse
was causing the earlier onset of schizophrenia.

"Most of us believe it may be bringing on schizophrenia earlier than
it would have otherwise occurred," he said.

"In some unfortunate people who are heavy users, they would have gone
through life with the vulnerability but it would never have been exposed."

Journalist and author Anne Deveson knows all too well the devastating
impact schizophrenia can have.

Her son Jonathan committed suicide after suffering from the disorder,
and she turned the story into the bestselling book Resilience.

"The sign was Jonathan ... started smoking quite early," she said. "A
lot of young people who are vulnerable, who have a psychotic illness
and are unable to cope with stress, they will use marijuana as a form
of relief."

Professor Mullen said there should be clear health warnings that while
occasionally using cannabis was not going to be a factor in
schizophrenia, heavy use could be.

"The people who are out there, who at 13 are smoking several bongs a
day, are in deep trouble," he said.

Dr Campbell said his work showed that many people using cannabis
experienced years of normality before succumbing to the psychosis
associated with schizophrenia. In men, it mostly happened in their
late 20s, while in women it could be as late as their 40s.

"The psych wards are full of these people," he said.

"There's a very clear division -- there's the cannabis group and the
non-cannabis group."

Dr Campbell said one study in Britain and The Netherlands had shown a
base rate of schizophrenia in Wales of 11 per 100,000 people, compared
with a rate in London and Amsterdam of 60 to 70 people per 100,000.

He puts this outcome down to the higher cannabis use in those cities
by young people between the ages of 12 and 21. 
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