Another study has found that marijuana use is colligate with change in the brain . The study compared the mentality of inveterate users with non - users and discovered the former had less mass in a area that is involved indecisiveness making and excited processing . However , they also found that this area prove increased connections with other brain neighborhood in drug user , suggesting that the brain could be re - wiring itself to make up for the shrinkage .
“ The changes in connectivity may be considered a fashion of compensating for the reduction in volume , ” state study authorFrancesca Filbey . “ This may explicate why chronic user seem to be doing fine , even though an important area of their brainiac is smaller in terms of volume . ”
Studies investigating the possible effect of smoke mass on the brain often produceconflicting results , which is probably due to the use of different methodology . To address this matter , researchers from theUniversity of Texas at Dallasused multiple magnetised resonance imaging ( MRI ) technique to build a comprehensive picture of the brain of almost 50 ganja users alongside 62 non - drug user that were age- and sex - touch . They also control for tobacco and alcohol use .
The marijuana smoking compartment were line as chronic users , consuming the drug three times a twenty-four hours on average . The participant had a wide age range and also bulge using the drug at dissimilar years , which allow the researchers to characterize change across life without developmental bias .
As described inPNAS , the researchers rule that , compare with controls , marijuana smokers had less volume in a learning ability region called theorbitofrontal cortex(OFC ) , which is involved in decisiveness qualification , emotion and controlling reward- and punishment - colligate behaviour . However , they also bump that this region had more morphological and functional connections with other mentality regions , which they speculate could be an adaptive reception to the reduction in OFC intensity .
They alsodiscoveredthat the earlier the participants started using marijuana , the greater the gain in brain connectivity in the OFC . Furthermore , the big increase in connectivity were found to appear as participants begun using marijuana . However , the re - wiring was found to fall after 6 to 8 year of chronic employment , although substance abuser still continue to display more connections than non - user .
Although the investigator found that , on modal , users had lower intelligence quotient compare to matched ascendancy , the difference were not link up to the observed brain changes as no correlations existed between IQ and OFC mass .
Marijuana advocates have alsocalled into questionthe usefulness of this study as it fail to appraise whether the observed changes were assort with untoward performance outcomes , such as mental ability or quality of life sentence .
“ It may be that these cannabis users are officiate in their daily life in a manner that is undistinguishable from controls , ” addedPaul Armentanoof the National Organization for the Reform of Marijuana Laws , “ in which case these imagery differences may hold niggling , if any , real - earth import . ”
Furthermore , the researchers accept that the report can not determine whether smoking marijuana caused the brain change or vice versa , and call forlong - term studiesto expression into this .
[ ViaPNAS , WebMDandUT Dallas ]
