Cannabis can harm young brains but may improve learning in older age

Cannabis might disrupt brain development in early adolescence – but it could actually improve memory and cognitive function in older adults.

In a 2021 study, Matthew Albaugh at the University of Vermont and his colleagues compared brain scans of nearly 800 teens taken five years apart. They found that adolescents who reported using cannabis during that time period experienced more shrinking in regions of the prefrontal cortex than teens who didn’t.

A follow-up study published last year, involving a different group of volunteers,…