Pubdate: Wed, 16 Apr 2014
Source: Morning Journal (Lorain, OH)
Copyright: 2014 Associated Press
Contact:  http://www.morningjournal.com/
Details: http://www.mapinc.org/media/3569

STUDY FINDS SIGNS OF BRAIN CHANGES IN POT SMOKERS

NEW YORK (AP) - A small study of casual marijuana smokers has turned 
up evidence of changes in the brain, a possible sign of trouble 
ahead, researchers say.

The young adults who volunteered for the study were not dependent on 
pot, nor did they show any marijuana-related problems.

"What we think we are seeing here is a very early indication of what 
becomes a problem later on with prolonged use," things like lack of 
focus and impaired judgment, said Dr. Hans Breiter, a study author.

Longer-term studies will be needed to see if such brain changes cause 
any symptoms over time, said Breiter, of the Northwestern University 
Feinberg School of Medicine and Massachusetts General Hospital.

Previous studies have shown mixed results in looking for brain 
changes from marijuana use, perhaps because of differences in the 
techniques used, he and others noted in Wednesday's issue of the 
Journal of Neurosciences.

The study is among the first to focus on possible brain effects in 
recreational pot smokers, said Dr. Nora Volkow, director of the 
National Institute on Drug Abuse. The federal agency helped pay for 
the work. She called the work important but preliminary.

The 20 pot users in the study, ages 18 to 25, said they smoked 
marijuana an average of about four days a week, for an average total 
of about 11 joints. Half of them smoked fewer than six joints a week. 
Researchers scanned their brains and compared the results to those of 
20 non-users who were matched for age, sex and other traits.

The results showed differences in two brain areas associated with 
emotion and motivation - the amygdala and the nucleus accumbens. 
Users showed higher density than non-users, as well as differences in 
shape of those areas. Both differences were more pronounced in those 
who reported smoking more marijuana.
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