24/10/2007 00:00:00
UK: Cannabis, 'a Double Edged Sword'
---
A new study suggests that THC, the active ingredient in cannabis may be
beneficial in the restriction of depression if taken in small amounts,
but can do just the opposite if too much is imbibed. The same applies to
its synthetic version.
The report of this study, which was led by Dr. Gabriella Gobbi of McGill
University, Canada, and Le Centre de Recherche Fernand Seguin was
published today in The Journal of Neuroscience.
In their neurobiological study on rats the scientists found proof that
cannabis in low doses increased the serotonin levels in the animal's brains.
This is significant because depression and other psychiatric conditions
like psychosis are caused by the lack of serotonin, a mood controlling
neurotransmitter.
It was also observed that the rats reverted to depression when they were
administered increased doses of the serotonin. Which is why the team
described cannabis as "a double-edged sword."
Although it is known that depression can be treated by enhancing the
available concentration of serotonin in the brain and that
anti-depressants like Celexa and Prozac are effective for this reason,
this study offered the first evidence that cannabis can also increase
serotonin, at least at lower doses.
Francis Bambico McGill PhD student and study author reported, “We know
from anecdotal evidence that (human) smokers of marijuana experience
good effects ... but they also experience unwanted effects. Some smokers
experience anxiety, agitation. But at very high doses and in certain
circumstances, it leads into depression-enhancing effects, particularly
if you take in a lot of cannabis at very high doses."
Dr. Gabriella Gobbi, psychiatrist and lead researcher remarked that
people treating themselves with cannabis as an anti-depressant can be
problematic because of the difficulty in controlling the dosage when it
is consumed as marijuana joints.
"Our research shows that excessive cannabis use in people with
depression poses a high risk of psychosis,” she said.
Gobbi revealed that she conducted the research upon noticing that quite
a number of her patients who suffered depression were used- to- be
cannabis smokers.
The researchers are now concentrating their research on a new group of
drugs known to enhance the effects of the brain's natural substances
that are released during high stress or pain, without the
anti-depressive side-effects. These drugs are natural endo-cannabinoids
to which cannabis has a chemical similarity.
"It's entirely possible to produce drugs that enhance endo-cannabinoids
for the treatment of pain, anxiety and depression," Gobbi said.
In another study, University of California researchers also found that a
moderate use of cannabis had the greatest impact on pain in 15
volunteers, but larger doses actually worsened the pain.
According to the study published in the journal, Anesthesiology, the
scientists from the University of California have termed quantity as
being key to its effectiveness.
Lead researcher Dr Mark Wallace, said that the findings could decide
future medications involving cannabis, both in pure and in drug form.
From the MS Society, Dr Laura Bell said, "Many people with MS report
benefits to symptoms such as pain from taking cannabis; however studies
to date on the effects of cannabis on pain are small and difficult to
draw firm conclusions from. We would be interested to see the results
from larger scale studies focused on people with MS."
http://www.earthtimes.org/articles/show/129581.html
Source:
http://www.ukcia.org/news/shownewsarticle.php?articleid=12932
Author:
Earth Times via UKCIA
|