POT MAY BE THE NEXT PROZAC

Causes new growth of brain cells; Researchers find marijuana-like drug
reduces anxiety and depression in rats

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, or so-called 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,"
Zhang said with a laugh in his Saskatoon office.

Well, good for rats anyway.

"We hypothesize cannabis or marijuana can produce a similar effect," 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
marijuana itself on rats' neurogenesis, Zhang said. He also cautions against
the assumption the drug will have the same effect on humans.

"There is a big gap between rats and humans," 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, 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 could drown.

What's more exciting to researchers than the potential connection between
smoking pot and easing lethargy and frayed nerves is the possibility 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, a Canada Research Chair in behavioural neuroscience and 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."

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, Zhang said.