Medical News Today reported this week about a new study that reveals that both past and present marijuana use is linked with worse verbal memory in middle age.

The researchers – led by Dr. Reto Auer of the University of Lausanne in Switzerland – published their work in JAMA Internal Medicine.

They used data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, which contains 25 years of marijuana exposure measurements, beginning in early adulthood.

In the final year, the study measured cognitive performance through standardized tests of verbal memory, processing speed and executive function.

Using the measurements from the final year of the study, Dr. Auer and colleagues investigated the association between cumulative years of marijuana use and cognitive performance in middle age.

The researchers found that past marijuana exposure was linked with worse verbal memory.

The researchers write that “with recent changes in legislation and the potential for increasing marijuana use in the United States, continuing to warn potential users about the possible harm from exposure to marijuana seems reasonable,” the researchers wrote.