Study links heavy marijuana use to reduced working memory in young adults

A new study from JAMA Network Open found that heavy marijuana use can damage working memory. The research involved 1,003 adults aged 22-36 who had used cannabis 1,000 or more times in their lives. The study revealed that 63% of participants showed reduced brain activity related to working memory tasks, such as following instructions. However, no link was found between heavy use and long-term memory. The lead researcher noted that more studies are needed to understand the long-term effects of heavy cannabis use. As of February 2025, 24 states have legalized recreational marijuana, and 40 states allow medicinal use.