|Photo by Sharon McCutcheon, Unsplash.com|
One week into the experiment, those who abstained from pot "performed moderately better on memory tests than they had at the beginning of the study," reports Laura Sanders of Science News. "One particular aspect of memory, the ability to take in and remember lists of words, seemed to drive the overall improvement. . . . Tricky tasks that required close monitoring of number sequences, and the directions and locations of arrows" did not seem to be affected.
"Scientists have struggled to find clear answers about how marijuana affects the developing brain, in part because it’s unethical to ask children to begin using a drug for a study," Sanders notes. So the researchers recruited 88 people 16 to 25 years old who reported using marijuana at least once a week, and offered 62 of them money to quit for a month. "Participants were paid more money as the experiment went along, with top earners banking $585 for their month without pot. . . . Urine tests showed that 55 of the 62 participants stopped using marijuana for the 30 days of the experiment."
The researchers from Massachusetts General Hospital and Harvard Medical School published their study in the Journal of Clinical Psychiatry.
Neuropsychologist April Thames of the University of Southern California told Science News that the study raises many interesting questions, such as whether there is a "point of no return" for the developing brain: “If somebody is using very heavily over a prolonged period of time, is there a point at which these functions may not recover?”
The researchers plan to conduct longer-term studies to answering that and other questions, Sanders reports: "While there’s still much to learn about how marijuana affects developing brains, the latest results suggest caution is needed, especially at a time when, as laws change, marijuana is becoming increasingly available in the United States and other countries."
“We should really be urging kids to delay using cannabis, particularly high-potency products, for as long as possible,” said neuropsychologist Randi Schuster, the lead researcher on the study.