Long-Term and Early Age Marijuana Use Can Lead to Abnormalities in the Brain

A new study conducted at the University of Texas at Dallas linked heavy, long-term marijuana use beginning at an early age to a smaller-volume orbitofrontal cortex, which is the area of the brain associated with decision-making and addiction.

The researchers, whose work was published in the Proceedings of the National Academy of Sciences, showed that compared to those who do not use marijuana, people who began smoking marijuana as young as 14 had less brain volume, or gray matter.

“The younger the individual started using, the more pronounced the changes,” said Dr. Francesca Filbey, the study’s principal investigator and associate professor at the School of Behavioral and Brain Sciences at the University of Texas at Dallas. “Adolescence is when the brain starts maturing and making itself more adult-like, so any exposure to toxic substances can set the course for how your brain ends up.”

The researchers also found increased brain connectivity in regular, long-term marijuana users. Connectivity allows the brain to make associations between thoughts, and helps promote adaptive learning. However, with higher volume, even these connections begin to deteriorate with chronic use.

The study examined 48 marijuana users, who all began smoking between the ages of 14 and 30. The average age of the study’s participants was 18, and participants used marijuana in some form about 3 times per day. Most said they had used the drug recreationally for about 10 years.

The 48 marijuana users were compared to 62 non-users, who had the same average ages and genders. The entire group was subjected to urine testing, an MRI to study the brain, and an IQ test.

In general, the IQ test showed that non-users scored higher. However, while there might be a link between long-term marijuana use and the scores on the IQ test, the researchers were careful to say that there is no definitive link to prove that marijuana use results in a lower IQ.

“While our study does not conclusively address whether any or all of the brain changes are a direct consequence of marijuana use, these effects do suggest that these changes are related to age of onset and duration of use,” Filbey said.

“This is a complex and interesting study that adds to the growing body of evidence that heavy marijuana use, particularly at a young age, is linked to significant adverse brain changes,” said Dr. Susan Weiss, associate director for Scientific Affairs at the National Institute on Drug Abuse. “This study showed that the orbitofrontal cortex, an area involved in reward, decision making and motivation, was smaller in heavy users and that other brain circuits were enhanced, likely to compensate for the diminished function in that region. Further prospective studies are needed to clarify this, but these mounting scientific findings certainly challenge the widespread belief that marijuana is a harmless drug.”

The study comes as support for recreational marijuana use and legalization is gaining ground across the country. In the recent midterm election, Alaska, Oregon, and Washington DC legalized recreational use of marijuana, joining Washington state and Colorado. However, while several other states have legalized medical marijuana, South Carolina currently has extremely limited medical marijuana allowances, which means that being caught with marijuana can lead to criminal charges.

If You Face Marijuana Charges, Including Drug Charges for Medical Marijuana Use, The Strom Law Firm Can Help

Possession of marijuana charges are all too common in South Carolina. If you or a loved one have been found with medical marijuana, you could face criminal charges ranging from misdemeanor to felony, depending on how much marijuana was in your possession, and what your intent was with the drug. The drug crimes attorneys at the Strom Law Firm can help. Do not let drug charges for medical marijuana hurt your reputation or your personal or professional future. We offer free, confidential consultations to discuss the facts of your case. Contact us today for help. 803.252.4800