Marijuana Use Found to Decrease Cognitive Function

Gabe Thomas

CNN is reporting that a new study has found that smoking marijuana regularly has harmful effects on a person’s cognitive function. The researchers who conducted the study randomly selected 5,000 adults age 18-30 and followed up with them at varying points for 25 years.

At the end of the 25 years the 3,400 participants still in the study had their cognitive function measured using standard tests of verbal memory, processing speed, and executive function.

Results showed that current marijuana use was associate with a decrease in processing speed and verbal memory, past marijuana use was associated with a decrease in verbal memory, and lifetime exposure to marijuana was shown to cause a decrease in all three.

The results from the verbal memory tests showed that for every five years of smoking marijuana, the subjects remembered one less word out of a group of 15.