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Barbara Streisand’s hauntingly beautiful song Memory has a telling lyric that should interest cannabis users:
Memory, all alone in the moonlight
I can dream of the old days
Life was beautiful then
I remember the time I knew what happiness was
Let the memory live again
Here’s the question: Does cannabis use interfere with our ability to Let the memory live again?
The short answer is no, at least for long-term memory. Cannabis use doesn’t erase memories already formed; for instance, childhood recollection remains in intact, says Harvard’s Peter Grinspoon: “It doesn’t cause any long-term or retroactive harm to your memory. It just affects memories while you’re under the influence.”
Though short-term memory formation is different and Grinspoon says it isn’t clear how long these memory dampening effects linger. “Some studies say the effect can last a couple of days, some say it lasts a couple of weeks. There’s no good evidence that it causes a long-term or permanent decrement [diminution] in your memory, but it definitely interferes with peoples ability to sort of encode new information.”
The culprit seems to be THC so Grinspoon advises:
I would say keep the doses of THC on the lower side, if you can. Add CBD. And then you do all the other things that are really good for your memory, like eat healthy, exercise, get enough sleep.
The literature agrees with him. In a recent book by three distinguished scientists, CBD: What does the Science Say? the authors cite two studies in support:
One says that “In human studies of cannabis users, cannabis with higher levels of CBD . . . has been associated with better cognitive performance, especially memory.”
The other is even more positive: “As well, a study examining the effects of THC . . . in a clinical population to twenty-four people with a range of neurological symptoms found that CBD reversed the THC-induced memory deficits.”
Finally, “No drug or medicine is without any side effects,” says Grinspoon. And keep in mind that such things as dosage, frequency of use, and the use of alcohol, tobacco and prescription medicines will also determine whether we’ll Let the memory live again.