Page 10 - My FlipBook

Creating a Controlled Test for Memory
Some people have wondered if marijuana users perform worse on
memory tests because they have a worse memory to begin with.
The best way to test the effects of marijuana on memory would be
a randomized trial, as is used in tests of legal drugs. In such a trial,
the researchers would start with two groups that had never used
marijuana. All subjects would take a memory test. Then one half
of the group chosen at random would start using marijuana. After
a certain period both groups would be tested for memory again.
The problem with conducting a test of this kind is that it would be
unethical, because marijuana is illegal under federal law and all
of its effects unknown. However, Randi Schuster, a researcher at
Massachusetts General Hospital in Boston, came up with another
way to see if marijuana was causing the memory loss.
In 2018 Schuster and her team recruited eighty-eight people
ages sixteen to twenty-five who used marijuana at least once a
week. The team tested the memories of these subjects. The re-
searchers then offered cash rewards to two-thirds of the subjects
if they would stop using marijuana for the duration of the test.
Those who agreed to stop using were given drug tests to ensure
they complied with the agreement. The other third was told to
continue using marijuana as before. This was the control group.
Both groups took memory tests once a week for the next month.
Schuster’s team found that the scores of those who stopped us-
ing marijuana improved after one week and remained at the same
level throughout the month. The scores of those who continued
to use marijuana showed a small improvement over the course of
the month, probably because they were getting used to the tests.
“This study suggests that cannabis abstinence is associated with
improvements in verbal learning,” state the researchers.
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Changes in Brain Cells
Marijuana use leads to memory loss because THC, an external
cannabinoid, attaches to the receptors in regions of the brain that
are vital for memory formation and disrupts their normal func-

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