What's the Rush, RI?

Advocating for Evidence Based Marijuana Policy

Monthly Archives: April 2016

Cannabis use associated with reduced dopamine release

Heavy cannabis use associated with reduced dopamine release in brain: Effect similar to other addictions.

Source:  Columbia University Medical Center: 
“Heavy cannabis use associated with reduced dopamine release in brain: Effect similar to other addictions.” ScienceDaily. 14 April 2016. <www.sciencedaily.com/releases/2016/04/160414214826.htm>.

ScienceDaily Summary:
Evidence of a compromised dopamine system has been found in heavy users of marijuana. Lower dopamine release was found in the striatum — a region of the brain that is involved in working memory, impulsive behavior, and attention. Previous studies have shown that addiction to other drugs of abuse, such as cocaine and heroin, have similar effects on dopamine release, but such evidence for cannabis was missing until now.

What’s the Rush, Research and Analysis Team Note:
Researchers also that in all participants lower dopamine release was associated with worse performance on learning and working memory tasks.  Heavy use was defined as daily for seven years beginning at age 16.

Journal Reference:
E van de Giessen, J J Weinstein, C M Cassidy, M Haney, Z Dong, R Ghazzaoui, N Ojeil, L S Kegeles, X Xu, N P Vadhan, N D Volkow, M Slifstein, A Abi-Dargham. Deficits in striatal dopamine release in cannabis dependenceMolecular Psychiatry, 2016; DOI: 10.1038/mp.2016.21

Cannabis Exposure Affects Fetal Growth Trajectories

Marijuana, the most common illicit substance used during pregnancy, can reduce birthweight by an average of 15 ounces over the course of a full term pregnancy. The 2009 study conducted in the Netherlands among 7,500 mothers was  Researchers also found a statistically significant reduction in head circumference.

The abstract and entire article published in the Journal of the American Academy of Pediatric and Adolescent Psychiatry can be found at:  http://www.sciencedirect.com/science/article/pii/S0890856709660731

MJ use during pregnancy linked to lower birth weights, increased need for postnatal intensive care and increased maternal anemia.

A meta-analysis of 24 related studies published April 5, 2016 indicates that babies born to mothers who use marijuana during pregnancy are 77% more likely to be born underweight; that twice as many will require postnatal intensive care; and that 36% of their mothers will develop anemia.  This study suggests that the public health impacts and costs of marijuana use would be much higher than proponents of legalization for recreational purposes have asserted.

The study, conducted by the University of Arizona School of Epidemiology published in the on line journal BMJ is available at http://bmjopen.bmj.com/content/6/4/e009986.


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