Schwartz emerged from years of Adderall dependency to a world that felt transformed. Suddenly it seemed to her that everyone had an internet-enabled case of A.D.H.D. and a prescription for speed. In 1990, an estimated 3 percent to 5 percent of American children were thought to have “disordered attention,” according to the Centers for Disease Control and Prevention, and some 600,000 children were prescribed stimulants. By 2013, 3.5 million children were on some kind of A.D.H.D. medication — increasingly Adderall, whose name, Schwartz points out, reflects its makers’ ambitions: “A.D.D. for all.”

“Adderall seems, on the surface of things, to fit so well with how life is, speed for the sped-up internet age,” Schwartz marvels. “It does not escape me that just as Adderall was surging onto the market in the 1990s, so was the World Wide Web, that the two have ascended in American life in perfect lock step, like a disease and a cure, made for each other.”

Here, the book steps away from straightforward memoir and starts flailing, taking up whatever aspects of attention that can hold Schwartz’s own. The narrative caroms between the science of A.D.H.D. to the promise of psychedelics in aiding focus to wan descriptions that feel grafted from Wikipedia on the work of David Foster Wallace, Simone Weil and William James, all of whom were consumed with the difficulty and holiness of attention. At one point Schwartz confesses, gratuitously: “I still didn’t know exactly what I was after, in this search for attention.”

The book’s most flamboyantly strange digression is in Schwartz’s extended, anguished defense of her father, Jonathan Schwartz, the longtime WNYC host who was fired in 2017 after “falling afoul of the Me Too movement,” as his daughter puts it. By indulging in such detours, the book enacts the very principles of distraction it describes.

Attention, Schwartz tells us, is not merely a matter of training the mind and eye on a subject; it is the practice of elimination, of determining what is inessential, what can be ignored. She tells us one thing, shows us another; we finish her book having gorged on trivia but finding basic questions unanswered: Where did Adderall come from? What is the relationship between the kinds of work we do now and the popularity of “performance drugs”? Schwartz seems to subscribe to the notion that A.D.H.D. evolves as a protective response to trauma; what is the prevailing opinion?

Instead, pointless, pallid excursions pad out the narrative: generic, listlessly described psychedelic conferences and ayahuasca ceremonies. Snooping around outside David Foster Wallace’s house in Claremont, Calif., Schwartz talks her way onto a neighbor’s property and tries to catch a glimpse of the patio where he hanged himself. She calls her boyfriend to crow: “I’m on a chair in a stranger’s yard looking at the place where David Foster Wallace died.” What is gained from such a story? Or from Schwartz breathlessly reporting on a Philip Seymour Hoffman sighting, shortly before his death? (Another addict, one who died at 46, just like David Foster Wallace!)

These celebrity anecdotes feel like gaudy bids for our interest — strange in a book that has, in its meandering way, argued for just the opposite approach. Recall the reverent absorption of the 19th-century naturalists, whom Schwartz herself writes about: Charles Bonnet, reverently absorbed in a single aphid. The loving, patient application of attention accepts no substitutes and is its own reward. It gilds the humblest subject; it allows us to see the story.