Effects of marijuana on brain activity
According to a new study marijuana contains ingredients that affect brain processing functions involving responses to certain visual stimuli and tasks.
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 often use this drug, in order to examine the effects of 9-tetrahydrocannabinol (9-THC) and cannabidiol (CBD) on regional brain function during salience processing which is how people perceive things around them.
They used functional MRI images to study each participant on 3 occasions after administration of 9-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.
The scientists stated that 9-THC significantly increased the severity of psychotic symptoms in comparison with placebo and CBD whereas there was no significant difference between the CBD and placebo conditions.
9-THC was more effective than placebo in reaction time to non-salient relative to salient stimuli. It was linked to modulation of both prefrontal and striatal function by 9-THC, increasing activation in the former region and weakening it in the latter.
This study also shows that the magnitude of 9-THC's effect on response times to non-salient stimuli was correlated with its effect on activation in the right caudate, the region where the physiological effect of 9-THC was associated with its induction of psychotic symptoms.
The scientists concluded that 9-THC can increase the aberrant attribution of salience and cause psychotic symptoms through its effects on the striatum and lateral prefrontal cortex.
When the effects of CBD were compared with 9-THC and placebo with respect to the visual task there was a "significant effect" in the left caudate with CBD increasing the response and 9-THC weakening it.
It means 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.
Comments
(2)Weed allows people to actually think and not just accept what is given to them at face value. Marijuana vs. any anti-psychotic or behavioral modification prescription pill is no contest. Weed is more effective with less side effects. This is why big pharma's worst nightmare is legal pot, or natural medicine that actually works.
drinkers have a high death toll
pot smokers have a nil death toll
hmm is it unhealthy no