San Diego, CA: Chronic marijuana use by adolescents may subtly impair certain neurocognitive skills, but this impairment is far less severe than the adverse effects associated with the use of alcohol, according to a review published in the January issue of the scientific journal Clinical EEG and Neuroscience.

Investigators at San Diego State University and the University of California at San Diego wrote: “Recent research has indicated that adolescent substance users show abnormalities on measures of brain functioning, which is linked to changes in neurocognition over time. Abnormalities have been seen in brain structure volume, white matter quality, and activation to cognitive tasks, even in youth with as little as one to two years of heavy drinking and consumption levels of 20 drinks per month, especially if [more than] four or five drinks are consumed on a single occasion. Heavy marijuana users show some subtle anomalies too, but generally not the same degree of divergence from demographically similar non-using adolescents.”

By contrast, studies have demonstrated that marijuana use by adults, even chronic use, is seldom associated with any long-term residual impact in cognitive skills.

Commenting on the UCSD/UCSD study, NORML Deputy Director Paul Armentano said: “This review affirms once again that cannabis, though not harmless, poses far less risk to the consumer than does alcohol. Given this premise, it is counterintuitive that our state and federal laws embrace the use of booze while stigmatizing and criminally prohibiting the use of marijuana by adults.”

For more information, please contact Allen St. Pierre, NORML Executive Director, at (202) 483-5500 or Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, “The influence of substance abuse on adolescent brain development,” appears in the journal Clinical EEG and Neuroscience.