Featured Research

from universities, journals, and other organizations

Human study shows greater cognitive deficits in marijuana users who start young

Date:
November 17, 2010
Source:
Society for Neuroscience
Summary:
New research shows that people who start using marijuana at a young age and those who use the greatest amount of marijuana may be the most cognitively impaired.

New research shows that people who start using marijuana at a young age and those who use the greatest amount of marijuana may be the most cognitively impaired.

The research was presented at Neuroscience 2010, the annual meeting of the Society for Neuroscience, held in San Diego.

Marijuana users show deficits in the ability to switch behavioral responses according to the context of a situation, also known as cognitive flexibility. The new study, directed by Staci Gruber, PhD, at McLean Hospital and Harvard Medical School, compared people's performance on the Wisconsin Card Sorting Task, a test of cognitive flexibility. During the task, people are shown four shown cards that differ in color, symbol, and value. Based on the rules they glean from these displayed cards, they must then sort a deck of cards. The participants are not told what the rules are -- only whether their sorting attempt is correct or incorrect. During the test, the researchers change the rules without warning, and participants must adjust accordingly. How a participant responds is a strong indicator of cognitive flexibility.

The researchers found that habitual marijuana users made repeated errors despite feedback that they were wrong. Marijuana users also had more difficulty maintaining a set of rules, suggesting an inability to maintain focus. Those participants who began using marijuana before the age of 16 and those who used the most marijuana showed the greatest impairment.

"Our results provide further evidence that marijuana use has a direct effect on executive function, and that both age of onset and magnitude of marijuana use can significantly influence cognitive processing," said Gruber. "Given the prevalence of marijuana use in the United States, these findings underscore the importance of establishing effective strategies to decrease marijuana use, especially in younger populations," she said.

Research was supported by the National Institute on Drug Abuse.


Story Source:

The above story is based on materials provided by Society for Neuroscience. Note: Materials may be edited for content and length.


Cite This Page:

Society for Neuroscience. "Human study shows greater cognitive deficits in marijuana users who start young." ScienceDaily. ScienceDaily, 17 November 2010. <www.sciencedaily.com/releases/2010/11/101116104202.htm>.
Society for Neuroscience. (2010, November 17). Human study shows greater cognitive deficits in marijuana users who start young. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2010/11/101116104202.htm
Society for Neuroscience. "Human study shows greater cognitive deficits in marijuana users who start young." ScienceDaily. www.sciencedaily.com/releases/2010/11/101116104202.htm (accessed July 24, 2014).

Share This




More Mind & Brain News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Do Obese Women Have 'Food Learning Impairment'?

Do Obese Women Have 'Food Learning Impairment'?

Newsy (July 18, 2014) Yale researchers tested 135 men and women, and it was only obese women who were deemed to have "impaired associative learning." Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins