Researchers have suggested through a new study that exposure to marijuana could lead to reduced intelligence quotient (IQ) and this is because marijuana hampers brain functioning.
Published in journal Acta Psychiatrica Scandinavica, the research by Lawson Health Research Institute, Ontario, Canada, researchers recruited a number of youth and divided them in groups based on their marijuana use and depression status. The groups were: those with depression who were not marijuana users, those with depression who were frequent marijuana users, frequent marijuana users without depression, and healthy individuals who were not marijuana users.
Participants were later divided into youth who started using marijuana before the age of 17 and those who began using it later or not at all. They then underwent psychiatric, cognitive and IQ testing as well as brain scanning. The results showed differences in brain function among the four groups in areas of the brain that relate to reward-processing and motor control.
Marijuana aka weed is one of the most used illegal substances in the world with children as young as 11 found to be using the substance. Researchers reveal in their study that people how have been exposed to marijuana from their younger years would end up having highly abnormal brain functioning in areas related to visuo-spatial processing, memory, self-referential activity and reward processing and this effectively meant that the IQ of the person will be affected as he/she grows up.
There have been studies that indicated a possible positive effect of marijuana on depressive symptoms; however the study didn’t find any such effect and says that there was no difference in psychiatric symptoms between those with depression who used marijuana and those with depression who did not use marijuana. The use of marijuana did not correct the brain function deficits of depression, and in some regions made them worse.
Previous studies have suggested that frequent marijuana users, especially those who begin at a young age, are at a higher risk for cognitive dysfunction and psychiatric illness, including depression, bipolar disorder and schizophrenia.
Researchers at Lawson Health Research Institute, in Ontario, Canada carried out the study and say that marijuana does not correct the brain abnormalities or symptoms of depression and instead its use from early age may have an abnormal effect not only on brain function, but also on IQ.