Quitting cannabis could lead to better memory and cognition

US research shows four weeks' abstinence improved memory, but not attention skills

Abstaining from cannabis for a month can boost the memory performance of regular users, according to a study of young people who used the drug at least once a week.

Researchers found that four weeks without cannabis led to a "modest but reliable" improvement in users' memory test scores, which could be sufficient to raise students' grades at school.