Pubdate: Fri, 14 Oct 2005
Source: Ottawa Citizen (CN ON)
Copyright: 2005 The Ottawa Citizen
Contact:  http://www.canada.com/ottawa/ottawacitizen/
Details: http://www.mapinc.org/media/326
Author: Janet French, The Saskatoon StarPhoenix
Bookmark: http://www.mapinc.org/mjcn.htm (Cannabis - Canada)

STUDY SUGGESTS MARIJUANA GOOD FOR YOU

Researchers Caution Benefits To Rats May Not Apply To Humans

SASKATOON - A University of Saskatchewan team has shown a 
marijuana-like drug reduces the symptoms of anxiety and depression in rats.

Using injections of a synthesized substance called HU210, which 
mimics one of the active ingredients in cannabis, associate professor 
of psychiatry Xia Zhang and his colleagues showed new growth of brain 
cells increased in rats. Other recent studies have linked that 
growth, known as neurogenesis, to a reduction in anxiety and depression.

The results were published yesterday on the website of the Journal of 
Clinical Investigation.

"The implication of this paper is that smoking marijuana is a good 
thing," Mr. Zhang said with a hearty laugh in his Saskatoon office.

Well, good for rats anyway.

"We hypothesize cannabis or marijuana can produce a similar effect," 
Mr. Zhang added.

The group, including researchers at Xijing Hospital in China and at 
the University of Maryland in Baltimore, have yet to test the effect 
of real marijuana on rats' neurogenesis, Mr. Zhang said. He also 
cautions against the assumption that the drug will have the same 
effect on humans.

"There is a big gap between rats and humans," Mr. Zhang said. 
"Realistically, we cannot judge these results from rats and apply 
them to a human situation. There's a huge difference. Our results can 
give (only) some indication or implication."

Although previous studies have shown alcohol, nicotine, opiates and 
cocaine reduce the growth of new brain cells, Mr. Zhang's paper is 
the first to show marijuana could have the opposite effect.

Because rats can't say how depressed they are, researchers used tests 
such as putting the rats in a swimming pool with no escape to 
determine how quickly they would give up swimming and resign 
themselves to a likely fate of drowning. The rats were plucked out of 
the pool before they actually drowned.

What's more exciting to researchers than the potential connection 
between smoking marijuana and easing lethargy and frayed nerves, is 
the possibility that a component of marijuana could be the next 
blockbuster antidepressant.

"Prozac is great, but it does have its problems, and its mechanism of 
action is similar to antidepressants we were using 40, 50 years ago," 
said Lisa Kalynchuk, an associate professor of psychology at the 
University of Saskatchewan.

"What we really need in the field is to develop new antidepressant 
drugs that are acting in new ways. Certainly, if we could get a drug 
that would act on these (cannabis) receptors and could actually 
alleviate depressive symptoms, that would be fantastic. It would be 
the next Prozac -- the next company to make billions of dollars."

There are problems with antidepressants currently on the market, she 
said, including side-effects such as dizzy spells, insomnia and 
impaired sex drive. Some drugs take a month to start working and 
others don't work on some people at all, she said.

But researchers would have to develop a better understanding of the 
mechanism by which HU210, or cannabis, work in the brain before they 
package them into pills, Mr. Zhang said.

Ms. Kalynchuk also questions whether the cannabis-like drug would 
have an effect on anxiety, since only one major study has shown a 
connection between increased neurogenesis and the reduction of anxiety.

HU210 is a purified substance, concentrated 100 times stronger than 
marijuana's active ingredient, tetrahydrocannabinol
- ---
MAP posted-by: Elizabeth Wehrman