REEFER MADNESS

Cannabis Policy Ignores Effect of Potent Pot on Schizophrenia

Scientific developments have established that as many as one in four
cannabis users is genetically at risk for developing schizophrenia or
a related psychotic disorder.

Given recent statistics from the United Nations citing Canada as the
industrial world's leading consumer of cannabis, this information
should set alarm bells ringing. Instead, Canada's mainstream media
responded as if someone had passed out The Happy Hippie Hymn Book that
no one noticed is 10 years out of date.

"Legalizing pot makes sense," intoned a National Post editorial.
Comparing cannabis to alcohol and tobacco, it asked where's the
"health footprint of our love for the weed?" A Globe and Mail article
titled "The True North stoned and free" giggled about Canada's "little
pot habit." Then there were the columnists. Suffice to say, only one
mentioned the word "psychosis" and that, only in passing.

Schizophrenia is a devastating brain disorder that typically produces
delusions, hallucinations, disturbances in problem solving, memory and
concentration, along with depressed mood, anxiety and social withdrawal.

The causes of schizophrenia are not fully understood, though
environmental stressors (childhood trauma, neglect) are thought to
interact with genes to produce disruptions in brain chemistry. Studies
conducted in Europe, New Zealand and the United Kingdom have
demonstrated cannabis is one of those stressors and that with their
rapidly developing brains, the young are particularly vulnerable. The
younger the user and the higher the potency of marijuana's active
ingredient, tetrahydrocannibol (THC), the greater the risk.

This information is causing headline news in the United Kingdom, but
on this side of the Atlantic no one seems to have noticed.

In a column two years ago, I described how genes and marijuana could
interact to increase risk of developing psychosis. The COMT gene,
consisting of a MET type and a VAL type, metabolizes dopamine, a brain
chemical that produces the "highs" characteristic of drug and alcohol
use. A MET/VAL mixture increases risk of psychosis from cannabis
twofold. A VAL/VAL mixture increases the risk 10 times. Since
one-quarter of the population is VAL/VAL, one-quarter is MET/MET and
the rest a mixture, the assessment that 25 per cent of youth are at
risk is probably conservative.

That column resulted from an interview with the world's pre-eminent
authority on marijuana and psychosis, Robin Murray. Lead and co-author
of countless studies on the subject, he is also professor of
psychiatry at King's College Institute of Psychiatry in London and
co-author of the standard textbook on this issue, Marijuana and
Madness. He also led criticism of British government policy that
ignored the mental health issues associated with marijuana use.

Paul Martin's Liberal government quietly withdrew its
marijuana-decriminalization bill shortly after publication of my
column. I like to think someone in that government had finally managed
to do their homework. But did anyone else?

Apparently not, even though the Canadian Journal of Psychiatry
featured marijuana and psychosis as the cover story of its summer 2006
issue. Recently, Addiction magazine predicted one-quarter of new
cases of schizophrenia by 2010 will result from cannabis smoking. In
March of this year, the Independent retracted and apologized for its
stand on decriminalizing marijuana: "Record numbers of teenagers are
requiring drug treatment as a result of smoking skunk, the highly
potent cannabis strain that is 25 times stronger than resin sold a
decade ago."

At least 10 per cent of that nation's schizophrenics could have
avoided the illness if they had not used cannabis, Murray said, while
British rapper J-Rock, a rehabilitated skunk addict, told the
Independent "if you're on skunk and you have a confrontation with
somebody, you feel almost untouchable."

"Skunk-induced paranoia," the Independent concluded, "is behind the
surge in violent crime." Remember, once you are psychotic, you don't
need continued hits of marijuana to behave aggressively or to
experience paranoia.

A UN spokesperson recently observed countries get the drug problems
they deserve. So by all means, let us discuss the relative merits of
legalizing or decriminalizing marijuana use. One scientist has
suggested it could be regulated according to potencies. Others are
finding possible benefits for psychosis that is drowned out by high
THC levels. But so long as that discussion ignores the overall health
effects of marijuana, Canada will get the drug problem it deserves.
Indeed, it has probably already arrived.