Cannabis Does Not Impair Brain Function
The term "working memory" was coined in the 1960s and gradually replaced the former terms "short-term store" or "short-term memory“ as more and more researchers began to use the concept of working memory to replace or include the older notions of short-term memory, thereby putting a stronger emphasis on the concept of manipulation of information instead of its passive maintenance.
The study published in the March issue of Addiction Biology was conducted by a team of Dutch scientists who monitored 49 heavy cannabis users. The researchers measured the brain activity of the participants when they performed a working memory task at baseline and in the follow-up three years later they repeated the test with 22 participants who were considered heavy cannabis users and continuously consumed cannabis five days a week on average for three years, 4 abstinent formerly heavy cannabis users and 23 non-cannabis-using participants as control group.
Previous studies had shown that cannabis can have a temporary effect on certain cognitive abilities, including attention and memory, but in this new study they found no changes in the working memory skills. Within the group of cannabis users, the working memory skills were not in correlation with cannabis use. This result suggests that sustained heavy use of cannabis does not change the working memory functionality and moreover, it suggests that the impact of cannabis on the memory may by totally overstated and not as harmful as some might think.
While the impact of cannabis on the brain continues to be debated, there remains little evidence that its use inevitably results in long-term impairment of the working memory abilities. However, there are possibly certain risk-factors, such as pre-existing disorders, that may influence the effects of long-term cannabis use.