Most people know that cannabis affects memory, sometimes negatively. It can also, however, restore cognitive function.
By Petar Petrov, Staff Writer for Terpenes and Testing Magazine
There’s a wide-spread belief that all memories dissolve much more quickly in cannabis fumes and smoke. Photographic memory and encyclopedic knowledge aren’t exactly the signature traits of the “stoner” stereotype, and probably rightfully so.
But human memory is no simple matter, and neither is cannabis. Multi-dimensional, eclectic, mysterious, ever-changing, subjective, personal – neither memories nor the effects of cannabis are easily pinned down, and it only gets harder when the two are tightly entwined.
Cannabis can make you remember, forget, reminisce, even make you “remember” things that didn’t actually happen – it’s the nature of the events and information that make the difference between memories and oblivion.
Cannabis and memory impairment
It’s no secret that cannabis, especially perpetual use, can envelope your mind and memory in a mist so thick it may never truly disperse.
For example, a study, published in the journal JAMA Internal Medicine found that heavy cannabis use permanently hinders verbal memory in middle age.  The researchers divided participants in two groups – heavy cannabis users in one and abstainers and occasional users in the other, and had everybody memorize a list of words. After 25 minutes, the heavy cannabis users remembered less of the words than the other group.
It’s important to remember the study focused on heavy cannabis users, as in people who have smoked daily for 5 years.
Cannabis and false memories
What’s more surprising though is that cannabis can actually trick people into thinking something has happened, or create “false memories”, as experts call them.
The Universitat Autonoma de Barcelona and the Bellvitge Institute for Biomedical Research conducted a study that probed these false memories.  However, instead of having participants memorize and recall words, researchers gave them a list of words, and after a few minutes, they presented them with another list, consisting mostly of the same words, but with a few added ones – some related to the original and some unrelated. Participants had to choose which words were originally on the list.
More cannabis users fell into the “trap” and were increasingly likely to believe that some of the new, related words were originally on the list. This might be due to the divergent thoughts and associations cannabis often causes, but that’s just speculation.
Cannabis and memory improvement
But arguably, the most surprising findings came last year from the University of Bonn.  A study found that cannabis can reverse the aging process of the brain in mice.
Because mice have a shorter life span, their cognitive abilities start to diminish as early as their 12th month. This is why scientists divided mice in three groups – two, twelve, and eighteen months-old, and gave them small quantities of THC over a period of four weeks.
Afterwards, the animals displayed cognitive functions and memory performance as good as the ones of a two-month-old mice.
“The treatment completely reversed the loss of performance in the old animals,” reported Professor Andreas Zimmer from the Institute of Molecular Psychiatry at the University of Bonn and member of the Cluster of Excellence ImmunoSensation.
Zimmer attributes this phenomenon to the similarity between THC and the effects of cannabinoids produced naturally in the body as the study found that the brains of mice without functioning receptors for THC age much faster.
“With increasing age, the quantity of the cannabinoids naturally formed in the brain reduces,” says Zimmer. “When the activity of the cannabinoid system declines, we find rapid aging in the brain.”
THC helped increase the number of links between the nerve cells in the mice’s brains, thus reversing the “molecular clock,” as Zimmer puts is.
Cannabis and nostalgia
While no studies establish a connection between cannabis and nostalgia, some of the more emotional, deeply human aspects of our relationship with the flower are best explained by real cannabis lovers rather than hard science and cold facts. Because if you break down nostalgia, you’ll see cannabis is a key that unlocks all its sources, directly or indirectly.
The flower can make you experience a moment on a deeper level, meaning when the moment passes, a more vivid, profound memory, stripped of all the fluff and irrelevant details can sink it –the moment’s pure, emotional essence.
We all know how much cannabis enhances music and art – and isn’t music one of the straightest modes of travel back in time? The more meaning and feelings you attach to a song, the closer to a memory you can get back to.
Smells also can trigger strong memories. Cannabis heightens our sense of smell, so the more you “feel” a smell, the more vivid your memory will be once the aroma hits your nostrils again.
There are even people who experience nostalgia for particular varieties of cannabis and particular harvests of the very same plant.
Even indirectly, cannabis is often the start of memories in the first place – it’s a pretext, a catalyst, that special extra spice to so many situations whose aftertaste lingers long after the moment has passed.
Ultimately, heavy cannabis use is rarely a good thing – not for memory, nor for anything else, just like nothing is ever really good in excess. But do it right, and not only will your memory be fine, but it might even become a large cassette with some fascinating retro films you can revisit every once in a while.
References Auer et al., “Association Between Lifetime Marijuana Use and Cognitive Function in Middle Age”, JAMA, 2016, 176(3):352–361.  Riba et al., “Telling true from false: cannabis users show increased susceptibility to false memories”, Molecular Psychiatry, 2015, 20: 772-777.  Bilkei-Gorzo et al., “A chronic low dose of Δ9-tetrahydrocannabinol (THC) restores cognitive function in old mice”, Nature Medicine, 2017, 23: 782-787.
Source: The Weed Blog