Most people think of cannabis as something that makes memories fuzzy. But new research suggests it can do something more surprising: make false memories feel real.
While cannabis is often associated with forgetfulness, a new study suggests that acute cannabis intoxication can also subtly distort memory, shaping not just what we recall, but how accurately we recall it. The findings expand on decades of research on cannabis and recall, pointing to a more complex effect on the brain’s memory systems.
To understand why, researchers are examining granular aspects of memory, such as false memory, source memory, prospective memory, and temporal order memory, and how each responds to THC. THC (tetrahydrocannabinol) is the primary psychoactive compound in cannabis responsible for the “high” or intoxicating, mind-altering effects.
What cannabis does to our memory
Although THC can produce desired effects such as euphoria, pain relief, and nausea control, it may also disrupt other processes, including memory formation. When we experience something, going for a hike, celebrating a birthday, different parts of our brain help process the thoughts, senses, and emotions that make up that moment. The hippocampus helps bind those elements into a memory that can later be retrieved.
Scientists generally describe memory as a three-part process: encoding (when the brain first takes in information), consolidation (when that information is processed and stored), and retrieval (when it is accessed later). “You are activating certain pathways to create a memory,” says a health expert, “and to recall something, you are trying to reactivate that same pathway.”
But how cannabis interacts with this process is not totally understood, since “drugs affect all three phases of memory differently,” says another health expert.
Part of the answer lies in the body’s endocannabinoid system, a signaling network that helps our bodies regulate numerous processes. This system includes naturally produced endocannabinoids, which carry the signals, and the CB1 receptors, where the message is received. THC, the primary psychoactive compound in cannabis, can also bind to CB1 receptors.
If you blast the system with THC, the THC hijacks the system. Instead of your CB1 receptors activating in a controlled pattern, they become overstimulate.
In the 2026 study, health experts randomly assigned 120 cannabis users to vaporize a placebo or doses of THC (20 or 40 milligrams). Participants were then given 21 memory tests, many of which had not previously been studied in relation to cannabis.
About 70 percent showed some level of impairment, including temporal order memory (remembering the sequence of events) and source memory (identifying where information came from). False memory and source memory showed the largest effect of cannabis.
