Pubdate: Thu, 01 Aug 2002
Source: Globe and Mail (Canada)
Copyright: 2002, The Globe and Mail Company
Section: Page A6
Author: Alanna Mitchell
Bookmark: (Cannabis - Medicinal)
Bookmark: (Cannabis - Medicinal - Canada)


Can it finally be medical proof of the old hippie bromide smoke your 
troubles away?

An international group of biochemists and pharmacologists has found that 
the brain can use cannabis to wipe away painful memories.

The findings, published yesterday in the journal Nature, are the results of 
experiments on mice. But the study's lead author, Beat Lutz of the Max 
Planck Institute of Psychiatry in Munich, said that the findings may have 
implications for humans.

"The obvious idea is to smoke marijuana and to get rid of bad memories," he 
said yesterday from Munich. "It can erase bad memories faster. But it has 
to be supported by psychotherapy."

The findings add to the mounting evidence that marijuana, an illegal drug, 
may have widespread medical benefits.

Canada is caught up in a policy struggle over marijuana. The Department of 
Health grows the stuff and has set up a system so that the sick can legally 
possess it for medical reasons. The federal government has a stash of 
several hundred kilograms but can't figure out how to distribute it to 
those in medical need, because selling and buying the substance is illegal.

Federal Justice Minister Martin Cauchon has been talking about 
decriminalizing the substance, and he admitted to smoking it.

Dr. Lutz's study will only add to the argument in favour of 
decriminalization. But it is also a landmark in medical terms because it 
deals with one of the central survival mechanisms of the vertebrate brain: 
the ability to spot danger and flee from it.

Scientists have long understood that the brain can reprogram itself not to 
flee if the danger goes away. That is called extinction of a memory. But 
scientists have not understood how it happens.

Dr. Lutz's research shows that the answer lies in the body's store of 
cannabinoids, or cannabis-like natural chemicals, produced whenever the 
body needs them. The brain has a receptor for these cannabis-like chemicals 
and can use them to help reprogram the response to a fear.

A problem is that the fear reaction can stick around when no longer needed. 
That can lead to panic attacks or paralyzing irrational fear.

Dr. Lutz said his finding could mean that a person in the grip of trauma 
might be able to summon up the terrible memory, with the help of a 
psychotherapist, then smoke marijuana to enhance the ability of the brain 
to extinguish the memory.

He said that smoking is by far the most efficient way of getting the 
substance to the brain, although researchers are looking at an aerosol to 
administer it straight to the lungs.

But Dr. Lutz was vehement in pointing out that simply smoking dope is not 
the way to take away the emotional pain. If this were to work, the patient 
would have to consciously retrieve the memory and concentrate on 
extinguishing it through the moderate, controlled use of cannabis. The 
practice of smoking dope to get happy is not going have this therapeutic 

Harold Kalant, a professor emeritus of pharmacology at the Centre for 
Addiction and Mental Health with the University of Toronto, also cautioned 
against misinterpretation of the findings. He noted that heavy, regular use 
of marijuana has well-documented negative effects.

And too much marijuana can diminish the brain's ability to lay down new 
memories, rather than aid the removal of bad ones. "This could make matters 
worse," he said.

Dr. Kalant also cautioned against believing that any drug is a magic 
medical bullet. He pointed out that morphine, cocaine and heroin were 
hailed with "wildly ecstatic claims" at first.

"Drugs are not a cure-all. Every drug has a downside," he said.
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