Health News

March 14, 2006

According to HealthDay News Greek researchers say the minds of long-term pot smokers don't process things as well as those of other people.

The findings of this marijuana study were published in the March 14 issue of Neurology. Researchers discovered that discovered that people who smoke at least four marijuana joints a week perform worse on a variety of mental tests including measuring memory, attention and verbal fluency. Those users who had smoked for more than 10 years show the most problems of all.

The study doesn't definitively link marijuana use to the cognitive problems, and it's possible that other factors could be to blame. Prior research has also offered conflicting findings about the mental effects of marijuana.

Greek researchers at the University Hospital of Patras gave cognitive tests to 64 people in a drug-abuse treatment program. Twenty were long-term marijuana users who had smoked for at least a decade. Twenty others had smoked pot for shorter periods and the remaining 24 hadn't used marijuana for at least two years. All the participants abstained from using marijuana for 24 hours prior to the tests.

Marijuana users tended to do worse on the tests, the researchers report. On a decision-making test, for example, long-term users were impaired 70 percent of the time, compared to 55 percent among short-term users and 8 percent among non-users.

In another test, the participants were asked to recall a list of words. The non-pot users did best, recalling an average of 12 of 15 words; the long-term users could only remember an average of seven. Research into the mental effects of marijuana is controversial, with some advocates of the drug claiming that its rumored mind-addling powers are a myth.