Medicine
Jill Margo Health editor Updated Jun 15, 2023 – 2.26pm
https://www.afr.com/policy/health-a...an-make-you-less-brainy-study-20230615-p5dgst
High performers who take drugs to sharpen their cognitive function may be blunting it, according to a new study by the Centre for Brain, Mind and Markets at Melbourne University.
Study authors based in the faculty of business and economics investigated the impact of “smart drugs” on productivity. They found that people in the top 25 per cent of performance without the drugs regularly ended up in the bottom 25 per cent with the drugs.
While such drugs are usually prescribed for people with
attention deficit hyperactivity disorder, they are often used, off label, by people without ADHD who want to enhance their analytic and decision-making ability.
“But there’s no quick fix,” said Elizabeth Bowman, who led the study. “There’s no shortcut to improving your cognition. People are always trying to find an edge, but there may be trade-offs that they’re not aware of.
“Smart workplaces require lots of different complex tasks and the need to move flexibly between them. All these drugs do is increase one particular kind of neurotransmitter – dopamine – in the brain. The brain is much more complicated than that.”
The study, published in the journal
Science Advances, casts new light on the practice. Previous studies have looked at the impact of smart drugs on simple cognitive tasks, such as remembering a list of digits or words, and have produced mixed results.
The new study used a complex task called the Knapsack Optimisation Problem, which presents participants with a set of items to pack into a container of fixed capacity. The items have different values, volumes, weights and other properties. If all can’t fit, the participants have to select a subset of items of maximum total value that will fit.
“Participants took 50 per cent longer, on average, to complete these cognitive tasks when they were taking a
drug like Ritalin compared to a placebo,” said Dr Bowman.
“They were trying more combinations, but their performance went down. In terms of productivity, all this extra effort was not paying off.”
While the study was small, it was high quality. Double-blinded and placebo-controlled, it involved 40 healthy participants who each came back four times. They were tested on a placebo and on three popular “smart” drugs: methylphenidate (Ritalin), modafinil and dextroamphetamine.
“Our research shows these drugs may actually be leading to healthy users working harder while producing a lower quality of work in a longer amount of time,” Dr Bowman said.
“The drugs did not increase their ability to solve the test correctly, and decreased the score they obtained compared to when they completed the task without drugs.”
In general, people taking the drugs experienced small decreases in accuracy and efficiency, along with large increases in time and effort relative to their placebo condition.
While high performers dropped most, participants who had a lower performance in a placebo condition only very occasionally exhibited a slight improvement after taking a drug.
Peter Bossaerts, senior author of the study and now a professor of neuroeconomics at the University of Cambridge, said more research was needed to understand the effects the drugs had on users without ADHD.
While the increase in dopamine was expected to increase motivation, a concurrent increase in the chemical norepinephrine was expected to cause an increase in effort. In turn, this was expected to lead to higher performance.
Professor Bossaerts said that as performance did not generally increase, questions remained about how the drugs were affecting people’s minds and decision-making.
The Melbourne team is also studying how acute stress affects these kinds of
decisions.
Jill Margo is the health editor, based in the Sydney office. Jill has won multiple prizes, including two Walkley Awards and is an adjunct associate professor at School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Australia. Connect with Jill on Twitter. Email Jill at jmargo@afr.com
