Pubdate: Sat, 20 Feb 2016
Source: Sun-Sentinel (Fort Lauderdale, FL)
Copyright: 2016 Sun-Sentinel Company
Author: Christopher Ingraham, The Washington Post


Findings Challenge Prior Studies on Marijuana Effects

New research published Wednesday in the journal JAMA Psychiatry found 
that using marijuana as an adult is not associated with a variety of 
mood and anxiety disorders, including depression and bipolar disorder.

This is a challenge to some previous research that has shown that 
marijuana use is associated with depression and anxiety.

The researchers examined the records of nearly 35,000 U.S. adults who 
participated in the National Epidemiologic Survey on Alcohol and 
Related Conditions. They examined the prevalence of marijuana use 
among the study participants in 2001 and 2002, then checked on the 
participants' rates of mental-health problems in 2004 and 2005.

After controlling for a variety of confounding factors, such as 
socio-demographic characteristics, family history and environment, 
and past and present psychiatric disorders, the study found that 
"cannabis use was not associated with increased risk for developing 
mood or anxiety disorders."

The study did find an association between marijuana use and later 
substance disorders, such as abuse of alcohol, tobacco, marijuana and 
other drugs. But this isn't necessarily surprising: It's fairly 
obvious that if you use a substance, you're putting yourself at risk 
of a substance-disorder.

People who use one drug often use others - think of the classic 
beer-and-combo. This is as true of marijuana as it is of, say, alcohol.

"The findings concerning cannabis raise the question of whether 
alcohol use also contributes to the risk of subsequent substance use 
disorders," lead author Mark Olfson of Columbia University said in an 
email. But that issue is beyond the scope of the current study, he added.

The findings on mental health are more interesting, given the 
conflicting picture portrayed by previous research.
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MAP posted-by: Jay Bergstrom