The most obvious effect of THC is the disruption of short-term memory. This means it will be harder to form new memories while high. THC also impairs the consolidation of short-term memories into long-term memories. This makes it difficult to remember what happened during the high — even after it wears off.
But THC does not impair your ability to recall existing memories. So, marijuana users will be able to remember things like their name and where they live, no matter how high they might get. Similarly, marijuana use does not lead to memory loss or dementia.
In fact, experts believe that the body’s endocannabinoid system — a biological system made up of naturally occurring, marijuana-like compounds — acts to regulate memory formation. Specifically, it seems to function as a filter of sorts, preventing the brain from being overloaded with irrelevant or useless memories.
The effects of THC on memory seem to depend on dose, with larger doses having a more severe effect. But studies also show that frequent users tend to be more tolerant to marijuana and its effects.
Some studies suggest that CBD may act to reduce the memory impairments of THC. However, not enough research exists to say for certain whether this is true.
While memory impairment is a downside for most marijuana users, THC can help some people forget bad memories.
In fact, studies show that the endocannabinoid system is directly involved with the extinction of negative memories. By acting on the endocannabinoid system, THC is believed to facilitate this extinction.
As a result, THC is believed to hold promise in treating anxiety disorders such as post-traumatic stress disorder (PTSD). Experts believe that marijuana can help patients with PTSD cope with traumatic memories by improving their ability to forget.
More at: Leaf Science