Getting high on cannabis is known to temporarily impact a person’s memory, making it harder to retain and recall new information. But how the brain copes with cannabis in the long run is less clear.
A decades-long study of more than 5,000 men in Denmark has now uncovered “no significant harmful effects of cannabis use on age-related cognitive decline.”
The findings stand in contrast to what has been found for a history of tobacco or excessive alcohol use, both of which are associated with faster cognitive decline. While more research is needed, especially among heavy, continuous cannabis users, this initial data is a positive sign.
In the new study, researchers at the University of Copenhagen measured cognitive decline using Denmark’s conscription board intelligence test, which is mandatory for men between the ages of 18 and 26. A total of 5,162 participants retook the test at around age 64, between 35 and 53 years after their first go.
At the follow-up, participants were asked if they currently used or had ever used cannabis. About 40 percent reported trying cannabis at least once. Roughly 10 percent said they were frequent users – at least twice a week – for less than a decade. Nearly 12 percent were frequent cannabis users for a decade or longer.
Even when accounting for other factors that can contribute to lower IQ scores, like education level, tobacco smoking, or binge drinking, models revealed significantly less cognitive decline among cannabis users compared to nonusers.
Specifically, the IQ decline for cannabis users was 1.3 points less.
Read the full article at ScienceAlert
