Cannabis & Memory: How THC Can Reshape Recollections | WSU Study

The effects of cannabis extend beyond the commonly understood experience of altered perception and relaxation. A newly published study from Washington State University reveals that cannabis intoxication can significantly disrupt multiple types of memory, and, surprisingly, even lead individuals to confidently recall events that never occurred. The research, published in the Journal of Psychopharmacology, adds nuance to our understanding of how THC – the primary psychoactive component in cannabis – impacts cognitive function.

Beyond Simple Recall: How Cannabis Reshapes Memory

While previous research has often focused on cannabis’s impact on basic recall, such as remembering lists of words, this WSU study takes a broader approach. Researchers found that THC consumption impaired not only simple memory tasks but also more complex forms of memory crucial for daily life. These include prospective memory – remembering to do things in the future, like taking medication or attending appointments – and source monitoring, the ability to recall where information originated. Which means that someone under the influence of cannabis might struggle to keep track of conversations or misattribute information to the wrong source.

The study involved 120 regular cannabis users who were randomly assigned to vaporize placebo cannabis, 20 milligrams of THC, or 40 milligrams of THC in a double-blind experiment. Interestingly, the researchers observed no substantial difference in memory impairment between those who received 20mg and those who received 40mg of THC. This suggests that even moderate doses of cannabis can cause considerable disruption to memory processes. “Most previous studies have only looked at one or two types of memory, like recalling lists of words,” explained Carrie Cuttler, senior author of the study and an associate professor of psychology at WSU. “This represents 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.”

False Memories and the Intoxicated Mind

Perhaps the most striking finding of the study was the increased likelihood of participants recalling words that were not presented to them. This phenomenon, known as false memory, raises concerns about the reliability of eyewitness testimony or personal recollections while under the influence of cannabis. The study authors suggest that THC may interfere with the brain’s ability to distinguish between internally generated thoughts and externally perceived information, leading to the creation of inaccurate memories.

This isn’t the first time researchers have explored the link between cannabis and memory. The Cannabis Research Center (CRC) at Washington State University, funded through the Washington State Liquor and Cannabis Board, has been a hub for advancing scientific knowledge on cannabis since the state’s legalization of recreational marijuana in 2012. The CRC supports a wide range of research projects, including those focused on the effects of cannabis on cognitive function.

Understanding the Implications for Daily Life

The implications of these findings extend beyond the laboratory. Impaired memory can have real-world consequences, affecting everything from academic performance and workplace safety to personal relationships and legal proceedings. For example, someone driving under the influence of cannabis might have difficulty remembering traffic signals or reacting to unexpected events. Similarly, an individual making critical financial decisions while intoxicated could struggle to accurately recall the details of their agreements.

It’s important to note that this study focused on regular cannabis users. The effects of THC on memory may differ in individuals with less frequent exposure to the drug. The study examined the effects of acute cannabis intoxication – the immediate effects of consuming THC – and did not investigate the long-term consequences of chronic cannabis apply on memory function.

Cannabis Research at WSU: A Growing Field

Washington State University is at the forefront of cannabis research in the United States. Beyond the CRC, the university also houses the Center for Cannabis Policy, Research and Outreach (CCPRO), which involves nearly 100 scientists working on a diverse range of cannabis-related projects. These projects address issues such as pain treatment potential, mental health impacts, effects on pregnancy, young adult use, and the legalization effects on crime.

Study Design and Limitations

The WSU study employed a rigorous double-blind design, meaning that neither the participants nor the researchers knew who was receiving placebo, 20mg THC, or 40mg THC. This helps to minimize bias. However, the study relied on self-reported cannabis use, which may be subject to inaccuracies. The study participants were all regular cannabis users, limiting the generalizability of the findings to individuals who rarely or never use cannabis. The study also focused on vaporized cannabis; the effects of other consumption methods, such as edibles, may differ.

What Comes Next: Ongoing Research and Future Directions

The findings from this WSU study underscore the necessitate for continued research into the effects of cannabis on cognitive function. Researchers are currently exploring the potential for interventions to mitigate the memory-impairing effects of THC, as well as the long-term consequences of chronic cannabis use on brain health. The CRC at WSU is actively funding research grants for graduate students and faculty to further investigate these important questions. For those interested in learning more about cannabis research opportunities at WSU, information can be found on their website, including details on how to request funds for cannabis research or apply for graduate student awards.

As cannabis legalization continues to spread across the globe, a deeper understanding of its cognitive effects is crucial for informing public health policies and educating individuals about the potential risks associated with its use.