“It only works as a cognitive enhancer insofar as you are dedicated to accomplishing the task at hand,” he said. “The number of times I’ve taken Adderall late at night and decided that, rather than starting my paper, hey, I’ll organize my entire music library! I’ve seen people obsessively cleaning their rooms on it.” Alex thought that generally the drug helped him to bear down on his work, but it also tended to produce writing with a characteristic flaw. “Often, I’ve looked back at papers I’ve written on Adderall, and they’re verbose. They’re belaboring a point, trying to create this airtight argument, when if you just got to your point in a more direct manner it would be stronger. But with Adderall I’d produce two pages on something that could be said in a couple of sentences.”

The drug, along with a steady stream of caffeine, helped him to concentrate during classes and meetings, but he noticed some odd effects; at a morning tutorial, he explained to me in an e-mail, “I alternated between speaking too quickly and thoroughly on some subjects and feeling awkwardly quiet during other points of the discussion.” Lunch was a blur: “It’s always hard to eat much when on Adderall.” That afternoon, he went to the library, where he spent “too much time researching a paper rather than actually writing it—a problem, I can assure you, that is common to all intellectually curious students on stimulants.

The drug, along with a steady stream of caffeine, helped him to concentrate during classes and meetings, but he noticed some odd effects; at a morning tutorial, he explained to me in an e-mail, “I alternated between speaking too quickly and thoroughly on some subjects and feeling awkwardly quiet during other points of the discussion.” Lunch was a blur: “It’s always hard to eat much when on Adderall.” That afternoon, he went to the library, where he spent “too much time researching a paper rather than actually writing it—a problem, I can assure you, that is common to all intellectually curious students on stimulants.

n 2004, he coined the term “cosmetic neurology” to describe the practice of using drugs developed for recognized medical conditions to strengthen ordinary cognition. Chatterjee worries about cosmetic neurology, but he thinks that it will eventually become as acceptable as cosmetic surgery has; in fact, with neuroenhancement it’s harder to argue that it’s frivolous. As he notes in a 2007 paper, “Many sectors of society have winner-take-all conditions in which small advantages produce disproportionate rewards.” At school and at work, the usefulness of being “smarter,” needing less sleep, and learning more quickly are all “abundantly clear.” In the near future, he predicts, some neurologists will refashion themselves as “quality-of-life consultants,” whose role will be “to provide information while abrogating final responsibility for these decisions to patients.” The demand is certainly there: from an aging population that won’t put up with memory loss; from overwrought parents bent on giving their children every possible edge; from anxious employees in an efficiency-obsessed, BlackBerry-equipped office culture, where work never really ends.

Chatterjee told me that many people who come to his clinic are cognitively preoccupied versions of what doctors call the “worried well.” The day I visited his office, he had just seen a middle-aged woman, a successful Philadelphia lawyer, who mentioned having to struggle a bit to come up with certain names. “Here’s an example of someone who by most measures is doing perfectly fine,” Chatterjee said. “She’s not having any trouble at work. But she notices she’s having some problems, and it’s very hard to know how much of that is just getting older.” Of course, people in her position could strive to get regular exercise and plenty of intellectual stimulation, both of which have been shown to help maintain cognitive function. But maybe they’re already doing so and want a bigger mental rev-up, or maybe they want something easier than sweaty workouts and Russian novels: a pill.