New study shows ‘smart’ drugs can decrease productivity in people without ADHD

New research from the University of Melbourne and University of Cambridge, published in Science Advances, shows healthy workers and students taking so-called cognitive enhancers, or ‘smart’ drugs, may be inhibiting their performance and productivity.

The drugs are commonly prescribed for Attention Deficit Hyperactivity Disorder (ADHD), but are also taken by people without the condition, based on a belief the drugs will enhance focus and cognitive performance.

In a double-blinded, placebo-controlled trial in Melbourne, 40 healthy participants took one of three popular ‘smart’ drugs (Methylphenidate, Modafinil or Dextroamphetamine), or a placebo, and were tested on how they performed. The test was repeated four times, at least one week apart, to measure how they each performed with the drugs and without (placebo condition).

In general, participants taking the drugs saw small decreases in accuracy and efficiency, along with large increases in time and effort relative to their placebo condition.

In addition, participants who performed at a higher level in a placebo condition tended to exhibit a stronger decrease in performance and productivity after receiving a drug. By contrast, participants who had a lower performance in a placebo condition only very occasionally exhibited a slight improvement after taking a drug.

Lead author of the study and researcher at the Centre for Brain, Mind and Markets at the University of Melbourne, Dr Elizabeth Bowman, said the results show the effectiveness of pharmaceutical enhancers when used by healthy people in everyday complex tasks has yet to be established.

“Our research shows drugs that are expected to improve cognitive performance may actually be leading to healthy users working harder while producing a lower quality of work in a longer amount of time,” said Dr Bowman.

Dr Bowman said that contrary to the belief that the drugs improve focus and cognitive ability in people without ADHD, the results of the research suggested otherwise.

“We found taking the drugs did not increase a participant’s ability to solve the test correctly, and it decreased the score they obtained compared to when they completed the task without drugs,” Dr Bowman said.

“We also found that participants took longer to complete the task, rather than being more efficient.”

Professor Peter Bossaerts, Leverhulme International Professor of Neuroeonomics at the University of Cambridge, said more research needs to be conducted to find out what effects the drugs are having on users without ADHD.

“It was expected, because of the increased dopamine the drugs induce, we would see increased motivation, and a concurrent increase in the chemical norephinephrine, would cause an increase in effort, which in turn would lead to higher performance,” Professor Bossaerts said.

“Performance did not generally increase, so questions remain about how the drugs are affecting people’s minds and decision making.”

See the full research report at Science Advances.

Media contact: Anna Knight