Pubdate: Fri, 20 Sep 2002
Source: Newsday (NY)
Copyright: 2002 Newsday Inc.
Contact:  http://www.newsday.com/
Details: http://www.mapinc.org/media/308
Author: Delthia Ricks, Staff Writer

DRUG IMPAIRS COORDINATION

Marijuana use triggers distinct changes in behavior and coordination, 
alterations that also have effects on perceptions of distance and time, 
experts said yesterday.

Coordination is a central motor ability that becomes impaired, doctors say, 
because the drug forces a relaxation of the muscles. The more marijuana 
that is inhaled, studies show, the longer the drug-induced relaxation 
lasts. This in turn leads to slowed reactions and compromising of spatial 
judgments.

A 1997 study of student athletes by the National Collegiate Athletic 
Association found that marijuana use by the students not only caused a lack 
of coordination but also impaired speech, a loss of critical thinking and 
problems with short-term memory. Because the drug has its most profound 
effects on vital chemical pathways in the brain, doctors found that it can 
have a substantial impact on mental health.

"The plant product now is very potent, and we see a fair number of people 
showing up in our hospital with psychosis," said Dr. Thomas Newton, medical 
director of the addiction program at the University of California, Los Angeles.

Within minutes of taking a drag on a marijuana cigarette, Newton said, the 
drug's active ingredient, tetrahydrocannabinol - THC - floods the 
bloodstream, impairing several key chemical pathways, particularly the 
dopamine-producing neurons in the brain. These neurons play a major role in 
coordination. The dopamine system is altered in certain disorders, such as 
Parkinson's disease, in which people lose the ability to walk with a smooth 
gait.

Studies by the National Institutes of Health have suggested that the lack 
of coordination helps explain why people who smoke marijuana and then take 
to the wheel are so often involved in automobile accidents.

One of those studies showed that 32 percent of injured drivers in a 
Baltimore hospital's shock-treatment unit had measurable levels of THC in 
their blood.

Newton said the drug on the streets today is at least 12 times more potent 
than the marijuana smoked 20 years ago. The result can be a more dramatic 
psychosis than doctors used to treat. "We have certainly had cases in which 
people don't get better all that quickly."

Marijuana is mildly addictive physically, he said, but the psychological 
desire to have it can become overwhelming. Continuous use, he added, leads 
to so demanding a desire that smokers "will spend all of their money just 
to get stoned."
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