After Years of Smoking Marijuana the Ability to Recall Words May be Affected

A new study suggests that for every 5 years a person smokes marijuana, their ability to recall common words declines.
The study, published in 'JAMA Internal Medicine,' looked at the marijuana habits of people ages 18 to 30... and then followed up 25 years later.
While 84% of participants said they used marijuana initially, less than 12% reported still smoking 25 years later.
In the follow-up, participants took standard cognitive tests that measured: Verbal memory (word recall), processing speed(like solving simple math problems) ... and higher-level skills that indicate how well different parts of the brain are connecting.
According to the study, the longer people used marijuana, the worse they did on all three fronts.
Taking into account other factors that could affect the results, researchers say only the association between long-term marijuana use and verbal memory persisted.
Specifically, the study suggests that for every five years someone smokes, they can recall one less word from a list of 15 words.
The study authors say they plan to invite participants back for a 30-year visit to undergo further cognitive testing.