ANXIETY HAS A LONG HISTORY THAT DATES TO THE ANCIENTS

With two new volumes analyzing the condition (“On Edge: A Journey Through Anxiety,” by Andrea Petersen, and “Hi, Anxiety,” by Kat Kinsman) following recent best-sellers by Scott Stossel (“My Age of Anxiety”) and Daniel Smith (“Monkey Mind”), the anxiety memoir has become a literary subgenre to rival the depression memoir, firmly established since William Styron’s “Darkness Visible” and Elizabeth Wurtzel’s “Prozac Nation” in the 1990s and continuing today with Daphne Merkin’s “This Close to Happy.”

While to epidemiologists both disorders are medical conditions, anxiety is starting to seem like a sociological condition, too: a shared cultural experience that feeds on alarmist CNN graphics and metastasizes through social media. As depression was to the 1990s — summoned forth by Kurt Cobain, “Listening to Prozac,” Seattle fog and Temple of the Dog dirges on MTV, viewed from under a flannel blanket — so it seems we have entered a new Age of Anxiety. Monitoring our heart rates. Swiping ceaselessly at our iphones. Filling meditation studios in an effort to calm our racing thoughts.

According to data from the National Institute of Mental Health, some 38 percent of girls ages 13 through 17, and 26 percent of boys, have an anxiety disorder. On college campuses, anxiety is running well ahead of depression as the most common mental health concern, according to a 2016 national study of more than 150,000 students by the Center for Collegiate Mental Health at Pennsylvania State University. Meanwhile, the number of web searches involving the term has nearly doubled over the last five years, according to Google Trends. (The trendline for “depression” was relatively flat.)

To Kai Wright, host of the politically themed podcast “The United States of Anxiety” from WNYC, which debuted this past fall, such numbers are all too explicable. “We’ve been at war since 2003, we’ve seen two recessions,” Wright said. “Just digital life alone has been a massive change. Work life has changed. Everything we consider to be normal has changed. And nobody seems to trust the people in charge to tell them where they fit into the future.”

For “On Edge,” Petersen, a longtime reporter for The Wall Street Journal, traveled back to her alma mater, the University of Michigan, to talk to students about stress. One student, who has ADHD, anxiety and depression, said the pressure began building in middle school when she realized she had to be at the top of her class to get into high school honors classes, which she needed to get into Advanced Placement classes, which she needed to get into college.

“In sixth grade,” she said, “kids were freaking out.”

This was not the stereotypical experience of Generation X.

Urban Dictionary defines a slacker as “someone who while being intelligent, doesn’t really feel like doing anything,” and that certainly captures the ripped-jean torpor of 1990s Xers. Their sense of tragic superiority was portrayed by Ethan Hawke’s sullen, ironic Troy in “Reality Bites,” who asserted that life is a “a random lottery of meaningless tragedy and a series of near escapes,” so one must take pleasure in the little things: a Quarter Pounder With Cheese, a pack of Camel straights.

For these youths of the 1990s, Nirvana’s “Lithium” was an anthem; coffee was a constant and Wurtzel’s “Prozac Nation: Young and Depressed in America,” about an anhedonic Harvard graduate from a broken home, dressed as if she could have played bass in Hole, was a bible.

The millennial equivalent of Wurtzel is, of course, Lena Dunham, who recently told an audience at the 92nd Street Y in Manhattan, “I don’t remember a time not being anxious.” Having suffered debilitating anxiety since age 4, the creator, writer and star of the anxiety-ridden “Girls” recalled how she “missed 74 days of 10th grade” because she was afraid to leave her house. This was around the time that the largest act of terrorism in United States history unfolded near the Tribeca loft where she grew up.

If anxiety is the melody of the moment, President Donald Trump is a fitting maestro. Unlike his predecessor, Barack Obama, a low-key ironist from the mellow shores of Oahu, the incumbent is a fast-talking agitator from New York, a city of 8.5 million people and, seemingly, 3 million shrinks.

In its more benign form, only a few beats from ambition, anxiety is, in part, what made Trump as a businessman. In his real estate career, enough was never enough. “Controlled neurosis” is the common characteristic of most “highly successful entrepreneurs,” according to Trump (or Tony Schwartz, his ghostwriter) in the 1987 book, “The Art of the Deal.” “I don’t say that this trait leads to a happier life, or a better life,” he adds, “but it’s great when it comes to getting what you want.”

Everything had to be bigger, bolder, gold-er. And it made him as a politician, spinning nightmare tales on the stump about an America under siege from Mexican immigrants and Muslim terrorists.

But if Trump became president because voters were anxious, as a recent Atlantic article would have readers believe, other voters have become more anxious because he became president. Even those not distressed by the content of his messages might find the manner in which they are dispensed jarring.

“In addition to the normal chaos of being a human being, there is what almost feels like weaponized uncertainty thrown at us on a daily basis,” said Kat Kinsman, the “Hi, Anxiety” author. “It’s coming so quickly and messily, some of it straight from the president’s own fingers.”

Indeed, Trump is the first politician in world history whose preferred mode of communication is the 3 a.m. tweet — evidence of a sleepless body, a restless mind, a worrier.

Some have suggested Twitter is a sort of crowdsourced poetry, but how many millions of miles is it from Auden: a cacophony of voices, endlessly shouting over each other, splintering what’s left of a “national discussion” into millions of tiny shards.

“We live in a country where we can’t even agree on a basic set of facts,” said Dan Harris, an ABC news correspondent and “Nightline” anchor who found a side career as an anti-anxiety guru with the publication of his 2014 best-seller, “10% Happier.” Harris now also offers a meditation app, a weekly email newsletter and a podcast that has been downloaded some 3.5 million times in the past year.

Push notifications. Apocalyptic headlines. Rancorous tweets. Countless studies have found links between online culture and anxiety. But if social media can lead to anxiety, it also might help relieve it.

The “we have no secrets here” ethos of online discourse has helped bring anxiety into the open, and allowed its clinical sufferers to band together in a virtual group-therapy setting. Hence the success of campaigns like #Thisiswhatanxietyfeelslike, which helped turn anxiety — a disorder that afflicts some 40 million American adults — into a kind of rights movement. “People with anxiety were previously labeled dramatic,” said Sarah Fader, the Brooklyn social media consultant who also runs a mental-health advocacy organization called Stigma Fighters. “Now we are seen as human beings with a legitimate mental health challenge.”

And let’s remember that we survived previous heydays of anxiety without a 24-hour digital support system. Weren’t the Woody Allen ‘70s the height of neurosis, with their five-daysa-week analysis sessions and encounter groups? What about the 1950s, with their duck-andcover songs and backyard bomb shelters?

That era “was the high-water mark of Freudian psychoanalysis, and any symptom or personality trait was attributed to an anxiety neurosis,” said Peter D. Kramer, the Brown University psychiatrist who wrote the landmark 1990s best-seller, “Listening to Prozac.” “And then there were substantial social spurs to anxiety: the World Wars, the atom bomb. If you weren’t anxious, you were scarcely normal.”

Scott Stossel, editor of The Atlantic, whose “My Age of Anxiety” helped kick off the anxiety memoir boom three years ago, urged people to pause, not for deep cleansing breaths, but for historical perspective.

“Every generation, going back to Periclean Greece, to second century Rome, to the Enlightenment, to the Georgians and to the Victorians, believes itself to be the most anxious age ever,” Stossel said.

That said, the Americans of 2017 can make a pretty strong case that they are gold medalists in the Anxiety Olympics.

“There is widespread inequality of wealth and status, general confusion over gender roles and identities, and of course the fear, dormant for several decades, that ICBMS will rain nuclear fire on American cities,” Stossel said. “The silver lining for those with nervous disorders is that we can welcome our previously non-neurotic fellow citizens into the anxious fold.”