New Study Finds Smart Drugs May Actually Undermine Cognitive Performance
The allure of “smart drugs” is simple: take a pill, get a brain boost. From medical students using Adderall to effective altruists running on modafinil, 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. However, a new study in the journal Science Advances finds that far from making users smarter, smart drugs seem to actually undermine cognitive performance.
The randomized, double-blinded study observed 40 participants 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 – methylphenidate, modafinil, and dextroamphetamine – and were then asked to complete a particularly challenging cognitive task: the knapsack problem. 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.
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.
The study design 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. 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. 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.
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 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.”