Frequent Cannabis Use May Damage Working Memory, Study Finds

Frequent Cannabis Use May Damage Working Memory, Study Finds

Cannabis joints on a table
New research shows that heavy lifetime use of cannabis is associated with reduced activity in areas of the brain involved in working memory. 24K-Production/Getty Images

  • Frequent cannabis use was associated with a small to medium decrease in working memory, a new study shows.
  • Working memory is needed for everyday tasks such as driving, remembering a shopping list and following verbal instructions.
  • The study is observational, so it can’t prove that cannabis damages the brain, but it adds to scientific evidence that cannabis may impact thinking.

More frequent use of cannabis may impair working memory, which could lead to problems with everyday tasks, a new study suggests.

“Working memory involves the ability to keep a small amount of information in the brain while performing a task,” said Natalie Klag, MD, assistant professor of psychiatry at The Ohio State University Wexner Medical Center in Columbus. “It is not just remembering the information, but being able to use it.”

“This can include things like following instructions, making plans or interacting with others in socially appropriate ways,” said Klag, who was not involved in the new study.

“Someone with impaired working memory may have difficulty following directions or completing a task that has multiple steps,” she told Healthline.

“They may also have difficulty with remembering questions or points in conversations long enough to wait until it is their turn to speak,” she said. “Or they may have difficulty with complex reasoning that involves considering multiple pieces of information to make a decision.”

The observational study, which was published January 28 in JAMA Network Open, does not prove that cannabis harms the brain, so the results should be viewed with some caution.

However, the new study adds to the scientific evidence that long-term cannabis use may affect cognitive abilities, including memory.

“I appreciate the fact that the researchers looked at seven different types of brain tests, but only one of them had a mild association,” said Sherry Yafai, MD, emergency medicine physician and director of integrated medicine at Providence Saint John’s Health & Wellness Institute in Santa Monica, CA.

“I would rather the researchers come out and say, ‘If you’re a young age, maybe it isn’t the right thing to smoke pot all day. And it’s not a good idea to be a heavy cannabis user,’” said Yafai, who was not involved in the new research.

Just like with any substance, it’s important to evaluate cannabis use to see if it’s causing any problems or negative effects. Sometimes, people may not realize the impact of cannabis use until they stop using it. If someone doesn’t want to completely stop using cannabis, healthcare professionals can help them reduce their use to avoid long-term consequences.

One thing to keep in mind is that the study didn’t look at the specific types or strengths of cannabis products used, so the results may not apply to everyone. It’s also worth noting that heavy cannabis users in the study were more likely to be male, have lower income and education levels, and use alcohol more frequently. This means the results may not be applicable to all groups of people.

Additionally, because the study was conducted a few years ago when cannabis wasn’t as widely available, the participants may have been more motivated to seek it out. It’s also important to consider if study participants were taking medications that could affect memory, as this wasn’t explored in the research.

Overall, it’s essential to be aware of the potential effects of cannabis use, especially on cognitive function. If you’re using cannabis for medical reasons, it’s important to discuss the benefits and risks with your doctor to make an informed decision. Remember, everyone’s situation is unique, so it’s crucial to consider all factors before making any decisions about cannabis use.