Study Shows Marijuana Use Affects Brain Size and Shape

Study Shows Marijuana Use Affects Brain Size and Shape

The recreational use of marijuana by young adults may alter the size and shape of their brains—specifically, regions that impact emotion and motivation—according to new research published in the April issue of the Journal of Neuroscience. The findings, presented in the article “Cannabis Use Is Quantitatively Associated with Nucleus Accumbens and Amygdala Abnormalities in Young Adult Recreational Users,” highlight the need for ongoing research on the long-term effects of marijuana use.

Aside from alcohol and tobacco, cannabis is the most commonly used recreational drug in the United States. The 2012 National Survey on Drug Use and Health, conducted by the US Department of Health and Human Services, found that 18.9 million Americans actively use marijuana, and a 2013 Gallup poll revealed that 36% of surveyed adults age 18 to 29 reported trying the drug. In addition, the US National Institute on Drug Abuse’s “Monitoring the Future 2013, Teen Drug Use Survey” reports that between 1993 and 2003, marijuana use among high school seniors increased by more than 10%, while its perceived harm decreased from 35.6% to 19.5%.

In the study, scientists from Northwestern University in Evanston, Illinois, and Harvard Medical School in Boston, used magnetic resonance imaging to compare the brains of 40 subjects between the ages of 18 and 25 who reported smoking marijuana at least once per week to those with little to no history of marijuana use. Imaging data revealed significantly different brain structures, with marijuana users’ brain anatomy appearing enlarged and altered in shape compared to nonusers. In addition, the researchers found that greater reported use correlated to an increased prevalence of these abnormalities.

Hygiene Connection E-Newsletter

May 2014