Chronic marijuana use affects our verbal memory

Chronic marijuana use affects our verbal memory

Study: Marijuana use deteriorates verbal memory
There is no denying that cannabis use has an impact on the human brain. However, scientists in this area often come to very different insights. A new study from Switzerland now shows that the long-term use of marijuana leads to a deterioration in verbal memory.

Effects on the brain
Marijuana is mainly used as an intoxicant, but it can also be used as a medicine. Its effectiveness has been scientifically proven for nausea and vomiting, among other things. And recently, a study confirmed that cannabis is helpful for migraines. In surveys, 90 percent of Germans support easier access to cannabis for patients. Critics like to point out the negative consequences of smoking pot. For example, there have been scientific studies in the past that indicated that marijuana use shrinks the brain. In the meantime, however, further studies have raised considerable doubts about the thesis that smoking pot reduces the IQ. A new study from Switzerland now indicates that cannabis use can lead to a deterioration in verbal memory.

Deterioration of verbal memory
As the researchers at the Université de Lausanne explained, according to a statement, the long-term use of marijuana leads to a deterioration in verbal memory. According to the information, the team led by Reto Auer had examined the cognitive performance of consumers in middle age. Previous research had shown a link between long-term use and cognitive impairment, especially when learning and remembering new information. It is said that no connection with a lower consumption has been proven.

Cognitive performance tested
For their analysis, the scientists used data from the “Artery Risk Development in Young Adults” study, which contains values ​​from 25 years of marijuana use. In the last year of the study, cognitive performance was assessed using standard verbal memory, speed of processing, and performance tests. Using this data, the researchers examined the relationship between years of consumption and cognitive performance in the middle years of life. 3,499 participants were tested, with 3,385 data on cognitive function available. 84.3 percent of them indicated consumption, 11.6 percent continued this consumption into middle age.

Previous consumption worsens memory more
The researchers found that past use was associated with poorer verbal memory among the study participants. However, other areas of cognition did not appear to be affected. According to the data, the values ​​decreased by 0.13 points per five years of previous consumption. This roughly corresponds to one in two participants remembering one word less in a list of 15 expressions. Despite the size of the study, the authors pointed out some possible limitations. For example, the information provided by the participants could not be reliable. In addition, measurements during marijuana use were not regular and were therefore not taken into account. It is also difficult to determine when the changes took place because the cognitive tests were performed only once. The scientists recently published their results in the specialist magazine "JAMA Internal Medicine". (ad)

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