Starting Age of Marijuana Use May Have Long-Term Effects on Brain Development

The age at which a teen begins using marijuana may affect typical brain development, according to researchers at the Center for BrainHealth at The University of Texas at Dallas.

In a paper published in Developmental Cognitive Neuroscience, scientists describe how marijuana use, and the age at which use is initiated, may adversely alter brain structures that underlie higher order thinking.

Findings show study participants who began using marijuana at the age of 16 or younger demonstrated brain variations that indicate arrested brain development in the prefrontal cortex, the part of the brain responsible for judgment, reasoning and complex thinking. Individuals who started using marijuana after age 16 showed the opposite effect and demonstrated signs of accelerated brain aging.

“Science has shown us that changes in the brain occurring during adolescence are complex. Our findings suggest that the timing of cannabis use can result in very disparate patterns of effects,” said Francesca Filbey, Ph.D., principal investigator and Bert Moore Chair of Behavioral and Brain Sciences at the Center for BrainHealth, in their news release. “Not only did age of use impact the brain changes but the amount of cannabis used also influenced the extent of altered brain maturation.”

The study was funded by the National Institute on Drug Abuse (NIDA).