Featured Research

from universities, journals, and other organizations

Marijuana use may hurt intellectual skills in multiple sclerosis patients

Date:
March 29, 2011
Source:
American Academy of Neurology
Summary:
Any possible pain relief that marijuana has for people with multiple sclerosis may be outweighed by the drug's apparent negative effect on thinking skills, according to new research.

Any possible pain relief that marijuana has for people with multiple sclerosis (MS) may be outweighed by the drug's apparent negative effect on thinking skills, according to research published in the March 29, 2011, print issue of Neurology, the medical journal of the American Academy of Neurology.

Related Articles


Some clinical trials have reported a mild benefit of marijuana on pain, bladder dysfunction and spasticity in MS, an auto-immune disease that affects the brain and spinal cord.

The researchers studied two groups of 25 people each between the ages of 18 and 65 with MS. One group used marijuana and the other reported no marijuana use for many years. Urine tests were used to confirm use or non-use of the drug. The groups were matched so there would not be significant differences due to age, gender, level of education, IQ before diagnosis, level of disability and duration of time with MS.

On average, the duration of marijuana use was 26 years. A total of 72 percent of users reported smoking marijuana on a daily basis while 24 percent reported weekly use and one person reported bi-weekly use.

Participants' cognitive skills were tested. The research found that people who used marijuana performed significantly worse with respect to attention, speed of thinking, executive function and visual perception of spatial relationships between objects. For example, on a sensitive test of information processing speed, those using marijuana scored approximately one third lower than non-users. Those who used marijuana were also twice as likely as non-users to be classified as globally cognitively impaired, defined as impairment on two or more aspects of intellectual functioning.

"Given that about 40 to 60 percent of MS patients have problems with cognitive function to begin with, any drug that may add to this burden is cause for concern," said study author Anthony Feinstein, MPhil, MD, PhD, with Sunnybrook Health Services Center and the University of Toronto in Ontario, Canada. "This study provides empirical evidence that prolonged use of inhaled or ingested marijuana in MS patients is associated with poorer cognitive performance, and these effects have to be weighed against any possible benefit of using marijuana for medicinal purposes."

The study was supported by the Multiple Sclerosis Society of Canada.


Story Source:

The above story is based on materials provided by American Academy of Neurology. Note: Materials may be edited for content and length.


Journal Reference:

  1. K. Honarmand, M. C. Tierney, P. O'Connor, A. Feinstein. Effects of cannabis on cognitive function in patients with multiple sclerosis. Neurology, 2011; 76 (13): 1153 DOI: 10.1212/WNL.0b013e318212ab0c

Cite This Page:

American Academy of Neurology. "Marijuana use may hurt intellectual skills in multiple sclerosis patients." ScienceDaily. ScienceDaily, 29 March 2011. <www.sciencedaily.com/releases/2011/03/110328161840.htm>.
American Academy of Neurology. (2011, March 29). Marijuana use may hurt intellectual skills in multiple sclerosis patients. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2011/03/110328161840.htm
American Academy of Neurology. "Marijuana use may hurt intellectual skills in multiple sclerosis patients." ScienceDaily. www.sciencedaily.com/releases/2011/03/110328161840.htm (accessed October 25, 2014).

Share This



More Mind & Brain News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Academic Scandal Shocks UNC

Academic Scandal Shocks UNC

AP (Oct. 23, 2014) A scandal involving bogus classes and inflated grades at the University of North Carolina was bigger than previously reported, a new investigation found. (Oct. 23) Video provided by AP
Powered by NewsLook.com
Working Mother Getaway: Beaches Turks & Caicos

Working Mother Getaway: Beaches Turks & Caicos

Working Mother (Oct. 22, 2014) Feast your eyes on this gorgeous family-friendly resort. Video provided by Working Mother
Powered by NewsLook.com
What Your Favorite Color Says About You

What Your Favorite Color Says About You

Buzz60 (Oct. 22, 2014) We all have one color we love to wear, and believe it or not, your color preference may reveal some of your character traits. In celebration of National Color Day, Krystin Goodwin (@kyrstingoodwin) highlights what your favorite colors may say about you. Video provided by Buzz60
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. 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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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