For women, the go-to was Mitchell’s “rest cure” which consisted of being confined to bed for four to six weeks, with every aspect of their lives controlled by physicians for that period. (Some men did the rest cure as well, just fewer.) They were spoon fed milk and soup, and not even allowed to read or move themselves—massages kept their muscles from atrophying. This treatment was made famous in Charlotte Perkins Gilman’s story “The Yellow Wallpaper,” in which a woman confined to an “atrocious nursery” slowly loses her mind. The story was inspired by Gilman’s own experience with the rest cure.

There were also some women, Gilman included, who used neurasthenia to challenge the status quo, rather than enforce it. They argued that traditional gender roles were causing women’s neurasthenia, and that housework was wasting their nervous energy. If they were allowed to do more useful work,they said, they’d be reinvesting and replenishing their energies, much as men were thought to do out in the wilderness.

Given the flexibility of neurasthenia, it makes sense that it could be used to argue two opposing points. The disease was both deeply cultural and deeply personal, and so provided a metaphorical framework for people to discuss how culture affected their lives and their health. “The appeal of neurasthenia as a disease was in part the way in which it allowed patients to reexplain the world to themselves,” Lutz writes.

And neurasthenia, in turn, did a lot to reorder the world. The national parks were pretty much created to give neurasthenics places to retreat into nature and heal. Recess time was established in schools because of the fear that sitting in a classroom all day was bad for children’s nervous systems. Christian Science as a religion grew up alongside neurasthenia, and its “think yourself well” doctrine, dubious as it was, did provide relief for some people suffering from the condition. The growing popularity of activities like bike-riding, traveling for vacations, and sports leagues was buoyed by the fact that these things were thought to help stave off neurasthenia.

Neurasthenia shaped so many things, but its true legacy is in how people talk about health and happiness and lifestyles. The more I’ve learned about neurasthenia, the more I’ve felt like I can hear its echoes in all the self-help books that promise to tell you how to be happy, in the Westernized yoga classes offering inner peace, in everyone fretting over whether the Internet is alienating or if babies should look at screens or if Americans are working too much and burning out. People haven’t stopped worrying about what the trappings of modern life are doing to us.

“How can Americans stay healthy while struggling with the demands of modern life?” This is the central question of Schuster’s book, and though he’s asking it about neurasthenia in the late 1800s, he could just as easily be asking it about stress today. (What is stress, anyway? Like, what is it? I went to the doctor recently with an ear problem and they told me it was probably stress. It was not illuminating.) Both neurasthenia and stress are vague concepts that make for easy scapegoats because they are so flexible. Both are grounded in reality but invoked in ways that exceed what is truly known about them.