The idea, and allure, behind “smart drugs” is simple enough: Take a pill, get a brain boost. From medical students using Adderall to cram for competitive exams to effective altruists running on the anti-narcoleptic modafinil to work more and sleep less, the rising consumer demand for cognitive enhancement is fueling a nootropics industry that’s eclipsing lunchtime martinis and cocaine-dusted financial transactions as the work/drug combination du jour.
In a global survey with tens of thousands of participants, non-medical smart drug use across US respondents rose from 20 percent in 2015 to 30 percent in 2017. Over the same time period, their use in France spiked from 3 percent to 16 percent, and the United Kingdom saw a rise from 5 percent to 23 percent.
Anecdotal evidence for the array of smart drugs suggests some benefits — sharper focus, stronger motivation, wellsprings of hustle to help keep up with a culture that valorizes the grind. But non-medical use has jumped far ahead of research, and what research does exist finds mixed benefits.
Now, a new study in the journal Science Advances from researchers at the University of Melbourne and the University of Cambridge — Elizabeth Bowman, David Coghill, Carsten Murawski, and Peter Bossaerts — finds that far from making users smarter, smart drugs seem to actually undermine cognitive performance.
The authors tested the effects of three drugs — methylphenidate (more commonly known through one of its brand names, Ritalin), modafinil, and dextroamphetamine (brand name Dexedrine, among others) — on a cognitive task designed to more closely mimic the complexities of real-world problems than past stimulant studies.
Far from simply concluding that smart drugs offer little benefit, the researchers found that the drugs actually seemed to leave users worse off. While study subjects worked harder while on the drugs compared to placebo, the “quality of effort,” or productivity, actually declined. The upshot is that smart drugs led users to spend more effort working while being less productive — not exactly a picture of cognitive enhancement.
“My advice would be: Stay away from them,” said Bossaerts, one of the co-authors and an economist at the University of Cambridge. “At the end of the day, the performance you reach is no better, or even worse, than without the drugs.”
The knapsack trials
The randomized, double-blinded study observed 40 participants (17 female, 23 male) between 18 and 35 years of age. Across a series of four separate sessions each spaced one week apart, participants received single doses of each drug. They were then asked to complete a particularly challenging cognitive task: the knapsack problem.
Here’s how it works: Imagine you have a knapsack with a weight limit, say 50 pounds. Laid out before you is a pile of different items, each with a particular weight and assigned value. The task is to find the combination of items that maximizes the value of what’s stored in the knapsack while remaining beneath the weight limit. In the study, the problem was carried out via computer, so participants could click items in and out of the bag, while seeing readouts of its total weight and value on the screen.
“It is often underappreciated just how difficult the tasks that humans encounter in modern life are,” the authors write in the study. “At an abstract level, many everyday tasks belong to a mathematical class of problems that is considered ‘hard,’ a level of difficulty not captured by cognitive tasks used in past stimulant studies.” The knapsack problem, in contrast, is meant to capture the same degree of difficulty that many real-world situations present.
The study authors had reason to expect that the smart drugs would make the task easier to complete. Methylphenidate, dextroamphetamine, and modafinil all increase dopamine and norepinephrine, neurotransmitters involved in motivation control and arousal, respectively. More dopamine and norepinephrine would seemingly translate into increased effort and higher performance.
That’s not how it turned out. Across all drugs, none actually improved the chances of finding the correct solution. Compared to their sober attempts, when participants were on any of the drugs, they tended to expend more effort, only to come up with worse combinations than they managed when not on the drugs.
“Effort” was measured in two ways: the amount of time spent searching for an answer before submitting their solution, and the number of “moves” of items in and out of the knapsack for each instance. The authors found that when participants took the drugs, they spent more time before submitting answers, and tried out more moves before settling on their final choices. These findings could suggest that the drugs successfully increased “motivation” — meaning, essentially, the willingness to keep working on a problem. But that drug-induced heightened motivation and additional work ultimately translated to lower-quality results.
In this case, “lower quality” meant lower productivity, as measured by the average gain in value per move while trying to fill the knapsack. Under the influence, participants’ efforts became less systematic and more random, leading to more wasted efforts, driving the decline in productivity.
Of course, no single study can pound the gavel on complex questions. The sample size was only 40, and no matter how clever an experimental design like the knapsack problem may be, generalizing the results to a blanket statement about productivity writ large, let alone whether they make one “smarter,” is a stretch. But the study design, Bossaerts explained via email, is the first that is “really difficult, in the mathematical sense. The knapsack problem is considered intractable even for computers.” The more difficult our experiments become, the more we might learn about how smart drugs actually affect outcomes in the real, messy world.
Productivity is not always smart
According to the study’s framework, what the authors call “genuinely smart drugs” would be ones “that not only increase effort but also enhance quality of effort” — in other words, working harder and more productively. But we shouldn’t be so quick to equate making oneself smarter to becoming more productive, or better at systematic thought.
Is it genuinely smart, existentially speaking, to take a drug that makes you “love work but hate people,” as Sebastián Serrano reported in Vice of modafinil? “You feel more energetic, motivated, focused, but that perception hides the fact that you’re becoming more erratic,” said Bossaerts. Answers growing more erratic is precisely what undermined productivity in the study, which brings up the question: What else might fare poorly under smart drugs?
Laboratory conditions cannot help but isolate some part of human life from all the rest. In fact, that’s sort of the point, to clear the noise and target a particular hypothesis. No matter how productivity, quality, or smarts are ultimately defined, there’s always the further question of what effects lie beyond the scope of study. In his self-experimentation, Serrano found: “Usually, I love walking, but because of the drug, it suddenly seemed like a complete waste of time.” Optimizing for productivity alone leaves a sort of spiritual vacuum that can send very smart people in search of what they’ve been missing.
Smart drugs, then, may reflect our cultural moment more than we care to admit. The pressures of meritocracy amid rising precarity, cutthroat educational demands that begin with hyper-competitive preschools, and the threat of job insecurity due to a renewed fear of automation all make the desire to find an edge perfectly intelligible. Who’s got time to optimize their lives around walks and spirituality?
Taken occasionally, Bossaerts said that smart drugs are close to harmless. But they can be mildly addictive, “so taking them more frequently may end up in a vicious cycle.” Most concerning, we have no long-term studies on the side effects of prolonged off-label use, and little understanding of how they might interact with other substances one takes. In the long-term, it’s a gamble users take at their own risk.
There are already consequences for those who rely on the drugs for daily functioning, however. When a medicine gets swept up in the smart drug hype, the rising demand yanks it away from those who depend on it for daily functioning. That’s already the case with both Adderall and Ozempic (a diabetes drug being used for weight loss) today.
All these caveats in place, if we could develop drugs that enhance both motivation and productivity without side effects, contraindications, or screwing over others who depend on them, why not? But for the rising numbers of smart drug users, if the knapsack problem is any indication, we don’t have them yet.