WSU Study Finds Cannabis Use Can Distort Memory and Increase False Recall

Researchers say even moderate doses of THC can broadly disrupt various memory systems

Published on Mar. 11, 2026

Got story updates? Submit your updates here. ›

A new Washington State University study found that people who consumed THC were more likely to recall words that were never presented and struggled with everyday tasks such as remembering to do something later. The study, published in the Journal of Psychopharmacology, is one of the most comprehensive looks yet at how cannabis affects memory, suggesting it can impair not only simple recall but also forms of memory people rely on in daily life.

Why it matters

The findings raise concerns about the potential impacts of cannabis use, especially as its use becomes more common in states like Washington. Accurate memory is crucial in many situations, from eyewitness interviews to remembering to complete everyday tasks. This study provides important insights into the short-term cognitive effects of cannabis, which remain poorly understood due to its federal classification as a Schedule I substance.

The details

Researchers recruited 120 regular cannabis users and randomly assigned them to vaporize placebo cannabis, 20 milligrams of THC, or 40 milligrams of THC. Participants then completed tests measuring various memory systems. Those who consumed cannabis performed significantly worse than the placebo group on most measures, with the strongest impacts appearing in false memory and source memory. Cannabis users were more likely to 'remember' words that were never presented and had more difficulty recalling where information came from. The study also found impairments in prospective memory, the ability to remember to carry out future tasks.

  • The study was published on March 10, 2026.

The players

Carrie Cuttler

An associate professor of psychology at Washington State University and the senior author of the study.

Ryan McLaughlin

An associate professor in the Department of Integrative Physiology and Neuroscience at Washington State University and a co-author of the study.

Got photos? Submit your photos here. ›

What they’re saying

“Most previous studies have only looked at one or two types of memory, like recalling lists of words. This is the first study to comprehensively examine many different memory systems at once, and what we found is that acute cannabis intoxication appears to broadly disrupt most of them.”

— Carrie Cuttler, Associate Professor of Psychology (dailyfly.com)

“If you have something you need to remember to do later, you probably don't want to be high at the time you need to remember to do it.”

— Carrie Cuttler, Associate Professor of Psychology (dailyfly.com)

What’s next

Researchers say more research is needed to fully understand the cognitive effects of cannabis, especially as its use becomes more widespread in states where it has been legalized.

The takeaway

This study highlights the potential risks of cannabis use, particularly in situations where accurate memory and recall are important. The findings suggest that even moderate doses of THC can broadly disrupt various memory systems, raising concerns about the drug's impact on daily tasks and activities.