



Published in the March issue of Addiction Biology , a team of Dutch scientists found no changes in the working memory abilities of heavy cannabis users who were monitored for three years.

The study “adds to the literature showing that regular cannabis use may not necessarily impair brain functioning,” explains lead author Janna Cousijn, PhD, a researcher at the University of Amsterdam’s Department of Developmental Psychology.

Working memory is the active part of memory which plays a key role in learning. It involves the short-term use of memory and attention to store information over brief periods of time.

Previous studies show that marijuana can have a temporary effect on certain cognitive abilities, including memory and attention.

But while marijuana’s impact on the brain continues to be debated, there remains little evidence that its use results in long-term impairment.

Dr. Cousijn and her colleagues conducted the study on 49 young adults, 22 who were considered heavy cannabis users and consumed marijuana five days a week on average.

The researchers measured brain activity of the subjects during various cognitive tasks at the start of the study and three years later. At follow-up, both cannabis users and non-users showed no changes in measurements of working memory.

“I believe that cannabis use may not necessarily affect brain functioning. However, certain risk-factors may increase the effects of long-term cannabis use,” concludes Dr. Cousijn.



