For some people, marijuana causes and rewarding high. For others, it produces serious psychiatric side effects.
Whether a person enjoys the experience or adverse effects from cannabis may well be decided by which region of the brain is acting upon, Western researchers have determined. [Thepsychologicaleffectsofmarijuanamaydifferbetweenindividuals:someexperiencehighlyrewardingeffectswhichmayleadtodependenceonthedrugwhileothersmayexperienceparanoiacognitiveproblemsorincreasedriskofdevelopingschizophreniaUntilnowitwasunknownwhichspecificregionsofthebrainwereresponsibleforthesehighlydivergenteffectsofmarijuana"saidStevenLaviolettePhDProfessoratWestern'sSchulichSchoolofMedicine&Dentistry
" Translational rodent research performed in our lab has identified highly specific target regions in the brain that seem to independently control the rewarding, addictive properties of marijuana versus the negative psychiatric side-effects associated with its use. "
The study, led by Laviolett e and postdoctoral fellow, Christopher Norris, Ph.D., is newly published in Scientific Reports and reveals critical new insights into how marijuana can produce such highly diverse psychological effects in different individuals.
By looking at THC's effect on a rat brain, the researchers showed that THC, the main psychoactive compound in marijuana, can produce highly rewarding effects in the front-part of a region of the brain called the nucleus accumbens.
The study showed that THC in this brain area not only produced highly rewarding effects in and of itself, it increased the addictive properties of opioid drugs like morphine and increased reward-related activity patterns in the neurons.
By contrast, THC in the posterior area of the nucleus accumbens region produced highly adverse effects
These included more schizophrenia-related cognitive and emotional symptoms and patterns of neuron activity similar to those found in people with schizophrenia.
"These are important because they suggest that some people have a very positive experience with marijuana when others have a very negative experience," said Norris.
"Our data indicate that the reward and aversion are produced by anatomically distinct areas, the different effects are likely due to genetic variation leading to differential sensitivity of each area.
Researchers reverse the negative effects of adolescent marijuana use
Christopher Norris et al. The Bivalent Rewarding and Aversive Properties of Δ9-tetrahydrocannabinol are Distributed by Dissociable Opioid Receptor Substrates and Neuronal Modulation Mechanisms in Distinct Striatal Sub-Regions, Scientific Reports (201
Why marijuana affects different people differently (2019, July 8)
retrieved 8 July 2019
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.