People who use so-called “smart drugs” to boost their mental performance tend to be worse at complex tasks despite tackling them with more enthusiasm, a study has found.
Drugs commonly prescribed to people with attention deficit hyperactivity disorder (ADHD) and narcolepsy, such as methylphenidate (sold under the brand names Ritalin and Concerta), Modafinil and dextroamphetamine, are sometimes used by people without those conditions who believe the drugs boost cognition.
According to the Australian drug regulator, the Therapeutic Goods Administration (TGA), the drugs are particularly popular among students, shift workers and people working in high-stress jobs, who obtain the drugs illegally online.
Researchers led by the University of Melbourne recruited 40 healthy participants aged between 18 and 35 and gave them one of the three drugs, or a placebo tablet with no drug in it. To prevent bias, neither the researcher or participant knew which substance was being given. None of the participants had the conditions the drugs are commonly prescribed to treat, such as ADHD.
The lead researcher, neuroscientist Dr Elizabeth Bowman from the university’s Centre for Brain, Mind and Markets, said participants were then asked to tackle a problem known as “the knapsack task”.
“Imagine if you have a bag and the bag has a weight limit, so it will only hold five kilograms. We present you with a number of items. Each item has a weight assigned to it, and a value, for example one dollar, or three dollars,” she said. “All you have to do is select items to go in the bag to maximise the value of what’s in the bag, without going over the weight limit.”
The benefit of the task is that it is complex with many combinations, Bowman said, and is more likely to mimic the kinds of problems people face daily, such as having a limited amount of money to spend at a supermarket, but needing to buy enough to feed their family for a few days.
“Those given the drugs spent much longer solving the task,” Bowman said.
“They also tried more combinations. But all that extra effort didn’t result in better performance. And as motivation, time and effort spent went way up, in general, performance went down. Increased productivity was not paying off.
“It just gave them more opportunities to be worse at what they were doing. It was like watching people put more petrol in a car in the hopes that it will go faster.”
In addition, participants who performed at a higher level after taking the placebo saw their performance and productivity plummet more sharply after receiving a drug. By contrast, participants who had a lower performance on the placebo only occasionally and slightly improved after taking a drug.
Bowman said previous studies examining the cognitive-enhancing effects of the drugs on people without conditions like ADHD or narcolepsy tended to ask people to perform more basic tasks such as memorising items, or tested reaction time.
“But there are very few modern workplaces where reaction times or memorising a list are the most important aspects to the job. You’re more likely to have to perform a variety of tasks of different complexities.”
She said the findings from her study may explain why “you hear stories of people taking these drugs and then focusing, but on the wrong things.
“You know, they take a pill to try and stay up to write an essay all night and end up cleaning the bathroom.”
The findings were published in the peer-reviewed journal Science Advances on Thursday.
Dr Hannah Kirk, a senior lecturer in developmental psychology based at the Turner Institute for Brain and Mental Health, said ADHD medication works by increasing the concentration of certain neurotransmitters in the brain, such as dopamine and serotonin.
“However, if an individual without ADHD who does not have reduced concentrations of neurotransmitters takes this type of drug then there is no clear mechanism for how improvements in behaviours can be made,” she said. “These findings, along with previous studies, highlight the importance of only taking medication that you have personally been prescribed for a diagnosed condition.”
The co-director of health and policy at the University of Sydney’s Brain and Mind Centre, Prof Ian Hickie, said people taking “brain-boosting” drugs without the conditions they are prescribed for is “incredibly popular, but dumb”.
“It’s an incredibly popular idea that if you take a little bit of this serotonin agent, a bit of this psychedelic, and mix it with some other substances, you’ll be at your best. It’s also incredibly dumb. People want to perform well, cognitively and emotionally. This is basically an exploitation of that desire.”
He said getting enough rest and sleep are more effective to boost performance, but added that high-pressure workplaces can “treat people like machines,” causing people to seek alternatives. “But the longer people work without resting or exercising, the more mistakes they make.”
