Frequent long-term cannabis smoking may have negative effects on a person’s verbal memory, a new study has found.
The study, conducted by researchers at the University of Lausanne, found that those who smoke cannabis daily over a period of five or more years had lower verbal memory — the ability to remember certain words — than those who did not smoke cannabis or smoked it less.
“We found a dose-dependent independent association between cumulative lifetime exposure to marijuana and worsening verbal memory in middle age,”
the authors of the study wrote.
Interestingly, the researchers observed that other areas of cognitive function, such as executive function or processing speed, appeared not to be affected by long-term cannabis use.
The study found the number of people who use cannabis daily was small. However, some drug policy experts have expressed concern that the loosening of cannabis laws — both on the state and federal level — could lead to a rise in use rates, and subsequently lead to more health problems.
The team of researchers examined data regarding the smoking habits of almost 3,400 Americans over a 25-year period. Following the study period, the test subjects submitted to a number of cognitive abilities tests. The tests included analyses on their memory and focus, among other areas.