Study drugs make healthy people worse at problem-solving, not better

livemint.com:

take the medications in the hope they will improve their concentration and ability to get things done. But a new paper suggests that this may be ill-advised. The drugs seem to make people slightly worse at solving problems, not better.

In the paper, published on June 14th in Science Advances, a group of researchers led by Peter Bossaerts, an economist at the University of Cambridge, tested how Adderall, Ritalin and another stimulant drug called modafinil (Provigil) affected 40 healthy people’s ability to perform optimisation problems. They used the “knapsack task", in which participants had to work out which items to put into a bag. The idea was to maximise the value of the items without exceeding the carrying weight of the sack.

The researchers used several trials of varying difficulty, each with different weight limits and lists of items. The participants visited the lab on four separate days. On each day they were given either a placebo pill or one of the drugs under study.

The study was double-blind, meaning neither the participants taking the pills nor the experimenters handing them out knew which had been administered on which day. They found that participants achieved slightly worse end-results on the task after taking a drug. The drugs did not impair people’s ability to find an optimal solution.

Participants managed this in around half of the trials, whether they took the drugs or the placebo pills. But they did cause a small drop in the value of participants’ knapsacks across all trials, by making the non-optimal solutions worse. Perhaps more striking was how drugs changed the way people attacked the task.