Have Questions?
We Have Answers!

Don't Know What To Do?

Call Now to speak with a Certified Treatment Assesment Counselor who will guide you every step of the way.
This is a free service • 100% Confidential

Treatment Help Request

Contact us now to get immediate help: 1-877-882-9275

Memory Affected by Long Term Marijuana Use

Long-term marijuana use causes memory, speed of thinking and other cognitive abilities get worse over time, but cognititive abilities are also affected in short-term pot smokers who use marijuana frequently.
Researchers studying heavy marijuana users (four or more joints per week) in Greece found that frequent marijuana users performed worse than non-users on test of cognitive abilities. Those who had smoked for more than 10 years had more problems with their thinking abilities than those who had used for five to 10 years.

"We found that the longer people used marijuana, the more deterioration they had in these cognitive abilities, especially in the ability to learn and remember new information," said study author Lambros Messinis, PhD, of the Department of Neurology of the University Hospital of Patras in Patras, Greece.

"In several areas, their abilities were significant enough to be considered impaired, with more impairment in the longer-term users than the shorter-term users."

Cognitive Abilities Slowed

The researchers made the following observations:

Compared to non-smokers, marijuana users performed worse in recall, recognition and executive functions of the brain.

In making decisions, long-term users showed a 70 percent impaired performance, compared to 55 percent for short-term users and eight percent for non-users.

In a test to remember a list of words that was read to them earlier, non-users remembered 12 of the 15 words, short-term users remember and average of nine words, and long-term users remembered an average of seven.

Frequent smokers performed worse on tests of cognitive abilities, including divided attention (ability to pay attention to more than one stimulus at a time) and verbal fluency (number of words generated within a time limit).

The study involved people ages 17 to 49 in a drug abuse treatment program in Athens, Greece. Twenty were long-term users, 20 shorter-term users and 24 control subjects who had used marijuana at least once, but not more than 20 times and not in the past two years.

Those who had used any other drugs, such as cocaine or stimulants, during the past year or for more than three months throughout their lives, were not included in the study. Before the tests were performed, all participants had to abstain from marijuana for at least 24 hours, according to a news release.

Source: The study was published in the March 14, 2006, issue of Neurology, the scientific journal of the American Academy of Neurology.

Find Top Treatment Facilities Near You

  • Detoxification
  • Inpatient / Residential
  • Private / Executive
  • Therapeutic Counseling
  • Effective Results
Call Us Today!


Speak with a Certified Treatment Assesment Counselor who can go over all your treatment options and help you find the right treatment program that fits your needs.



Discuss Treatment Options!

Our Counselors are available 24 hours a day, 7 days a week to discuss your treatment needs and help you find the right treatment solution.

Call Us Today!