Marijuana Smokers Exhibit Virtually No Change

New York, NY-(ENEWSPF)-July 9, 2010. Experienced marijuana consumers exhibit nominal changes in cognitive performance after inhaling cannabis, according to clinical trial data published online this week in the journal Pharmacology, Biochemistry, and Behavior.
Investigators at Columbia University in New York and the San Francisco Brain Research Institute assessed acute marijuana-related effects on cognitive functioning in 24 volunteers who reported consuming the drug at least 24 times per week.
Researchers determined that participants’ overall performance accuracy on episodic memory and working memory tasks “was not significantly altered by marijuana.”
Authors concluded: “The present findings show that smoked marijuana produced minimal effects on episodic and spatial working memory of near-daily smokers. The overall response accuracy on the word recognition and working memory tasks was unaffected by marijuana, although smoked marijuana did increase the amount of time participants needed to complete these tasks.
“This pattern of effects is consistent with results previously reported by other researchers studying the acute effects of marijuana on cognitive performance of regular users. … The finding … stands in contrast to previous findings in occasional smokers who showed reduced accuracy on these same tasks after marijuana. … The observation that frequent users’ response accuracy is not altered after marijuana smoking to the same extent it is for infrequent users … suggests that near-daily marijuana smokers may have developed tolerance to some marijuana-related behavioral effects.”