About Careers MedBlog Contact us

Regular Marijuana Smoking Can Lead to Long-term Drop in IQ

by Vishnuprasad on August 12, 2014 at 1:52 PM
Font : A-A+

 Regular Marijuana Smoking Can Lead to Long-term Drop in IQ

Contrary to the popular belief, a recent research has shown that regular use of marijuana is bad for the brains of teens. According to psychologists at the American Psychological Association (APA), frequent marijuana use among teenagers can lead to cognitive decline, poor attention and memory and decreased intelligence quotient (IQ).

Krista Lisdahl, director of the brain imaging and neuropsychology lab at University of Wisconsin-Milwaukee, said that brain imaging studies of regular marijuana users have shown significant changes in their brain structure, particularly among adolescents.


Lisdahl reiterated that young people who become addicted to marijuana lose about six IQ points by the time they reach adulthood. "It needs to be emphasized that regular cannabis use, which we consider once a week, is not safe and may result in addiction and neurocognitive damage, especially in youth," she said.

Psychologists also discussed the possible public health impact of marijuana legalization. They opined, when considering legalization, policymakers need to address ways to prevent easy access to marijuana and provide additional treatment funding for adolescent and young adult users.

According to Lisdahl, marijuana use is increasing among youth in the US. She cited a 2012 study that showed daily pot use among high school seniors had more than doubled from the 1990s, from 2.4 per cent to 6.5 per cent.


Marijuana is a preparation of the cannabis plant intended for use as a psychoactive drug and as medicine. It was a well-established medicine until it was federally criminalized in 1937.  According to the international sources with Medindia, it is the most commonly used illegal drug in the U.S. and the world.

However, a recent survey has showed that public support for legalizing marijuana use in the US is at an all-time high of 54%, though it is virtually unchanged from last year (52%). Survey states that there is even more agreement that people convicted of possessing small amounts of marijuana should not serve time in jail.

 Where is Marijuana legal?

 Colorado and Washington became the first states to legalize marijuana in 2012, when voters approved legalization.  Marijuana remains illegal under federal law, although the US administration has said it will permit state-level norms to stand without much federal interference.

This year, Alaska, Oregon, and Columbia will vote on whether marijuana should be legal for recreational and medical purposes.

Outside the US, Uruguay became the first country in the world to fully legalize marijuana in 2013. The Netherlands permits citizens to keep and cultivate some marijuana, and police let coffee shops sell marijuana as long as they don't sell to minors or break other major rules. According to multiple reports from experts, visitors, and defectors, North Korea either has no law restricting marijuana or the law goes effectively unenforced.

Source: Medindia

Recommended Reading

This site uses cookies to deliver our services.By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use  Ok, Got it. Close

Regular Marijuana Smoking Can Lead to Long-term Drop in IQ Personalised Printable Document (PDF)

Please complete this form and we'll send you a personalised information that is requested

You may use this for your own reference or forward it to your friends.

Please use the information prudently. If you are not a medical doctor please remember to consult your healthcare provider as this information is not a substitute for professional advice.

Name *

Email Address *

Country *

Areas of Interests