Child Health

Teenage Marijuana Use May Damage Cognitive Function

 From the knockdown that legalized pot took in the California election to Arizona approving the use of medical marijuana, rarely a day goes by without good old cannabis hitting the headlines. Marijuana has been a controversial drug for most of the twentieth century with both citizens and lawmakers jumping into the fray on one side or the other. One day there is a report on the benefits, the next the hazards of the illicit “weed.” Rarely is there enough evidence to sway anyone from changing camps. Today’s story on a new study probably won’t be much different, but it does speak to the use of marijuana in adolescence.

Neuroscientists out of McClean Hospital in Massachusetts conducted a small study testing mental focus and flexibility. They found that damage to the brain can be more severe if started prior to the age of 16, and that starting prior to that age leads to more regular use of the drug.

“Age really does matter,” said Staci Gruber, director of the Cognitive and Clinical Neuroimaging Core at McLean. “Early onset is related to more frequent and higher magnitude of use and significantly greater impairment on these tasks, which ultimately could result in greater difficulty with everyday life activities and decision-making. That’s a problem.”

The study, conducted with only 33 marijuana users and 26 non-users, tested cognitive function, memory and the ability to focus with distraction. In all cases, the users scored worse than the non-users, and the more grams of marijuana they smoked per week, the worse they did. Even after participants were given the corrections, many continue to make the same mistakes.

Brain development occurs into a person’s twenties, during which time the brain is most vulnerable. Research such as this can help to formulate guidelines for possible future legalization, keeping it out of the hands of minors, similar to laws for alcohol use.