We learn that there are two
active ingredients and that one is producing psychotic symptoms and the other
is not. I am not too sure where any of
this goes as nothing is said about the individual effects that might drive usage.
It is still intriguing and must
lead to a separation of the two components in terms of future drug testing and
perhaps the elimination of prohibition for one element at least.
At least we are now seeing some
science progressing in the field. The science has been stalled for decades
because of prohibition.
Brain Imaging Study Evaluates Effects of Ingredients in Marijuana On
Brain Functioning During Reactions to Visual Stimuli
ScienceDaily (Jan. 2, 2012) — Different ingredients in marijuana
appear to affect regions of the brain differently during brain processing
functions involving responses to certain visual stimuli and tasks, according to
a report in the January issue of Archives of General Psychiatry, one of
theJAMA/Archives journals.
Sagnik Bhattacharyya, M.B.B.S., M.D., Ph.D, at the Institute of
Psychiatry, King's College in London, and colleagues studied 15 healthy men,
who were occasional marijuana users, to examine the effects of
Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) on regional brain
function during salience processing, which is how people perceive things around
them.
The authors used functional MRI images to study each participant on
three occasions after administration of Δ9-THC, CBD or placebo. Study
participants performed a visual oddball task of pressing buttons according to
the direction arrows on a screen were pointing, as a measure of attentional
salience processing.
"Pairwise comparisons revealed that Δ9-THC significantly increased
the severity of psychotic symptoms compared with placebo and CBD whereas there
was no significant difference between the CBD and placebo conditions," the
authors conclude.
Δ9-THC had a greater effect than placebo on reaction time to nonsalient
relative to salient stimuli. This was associated with modulation of both
prefrontal and striatal function by Δ9-THC, augmenting (increasing) activation
in the former region and attenuating (weakening) it in the latter.
"Moreover, in the present study, the magnitude of Δ9-THC's effect
on response times to nonsalient stimuli was correlated with its effect on
activation in the right caudate, the region where the physiological effect of
Δ9-THC was linked to its induction of psychotic symptoms," the authors
write.
They conclude that "collectively, these observations suggest that
Δ9-THC may increase the aberrant attribution of salience and induce psychotic
symptoms through its effects on the striatum and lateral prefrontal cortex."
When the effects of CBD were contrasted with Δ9-THC and placebo with
respect to the visual task there was a "significant effect" in the
left caudate with CBD augmenting (increasing) the response and Δ9-THC
attenuating (weakening) it.
"These effects suggest that CBD may also influence the effect of
cannabis use on salience processing -- and hence psychotic symptoms -- by
having an opposite effect, enhancing the appropriate response to salient
stimuli," the authors wrote.
So... Tell us what your point is.
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