Agoraphobia, from the Greek agora for marketplace, today afflicts 3.2 million adult Americans, a number no doubt underestimated because agoraphobics are notoriously hard to count.
Originally conceived as the fear of wide-open spaces, the condition once conjured Munch's (an agoraphobic himself) The Scream: a weakened individual cowering in the frenetic modern city. This definition has since mutated. Today it's understood as the end game of panic anxiety disorder, the fear of one's own fear response - being driven mad by the inescapable thunder of a panic attack. Because of this fear, agoraphobics map out safe zones (their homes, usually) and retreat into private worlds, which can become prisons.
Darwin had it. Dido has it. Emily Dickinson and Kim Bassinger, too. It's been called "Greta Garbo Syndrome" after the actress who holed up in her New York apartment for almost 50 years with only her famous declaration "I just want to be alone" to guard her door.
Lately I've been noticing how much harder it is to get people I know to leave their neighbourhoods. To put down their phones. To read or watch or listen to things they don't already know they'll enjoy.
It's not just my sphere; Americans at large are more isolated than ever, and more anxious, across many disparate groups: children, soldiers, college students, women. We increasingly fear things we have no reasonable cause to fear. While the number of clinically diagnosable agoraphobics hasn't increased, something that reeks of agoraphobia seems to be presenting itself all around me.
I know what it looks like. My mother's agoraphobia began in her early 20s. It started after a panic attack while she was driving. First she stopped using highways; then she avoided left turns. After that came a gradual narrowing. Friends and hobbies that required outward ventures were scuttled. Her interests migrated indoors: reading, art, crafts, cooking.
By the time I was about 5, she didn't leave our house if she could help it. At school, I'd hear about "vacations" from my classmates and had trouble parsing the idea. Forget airplanes or road trips - my mother couldn't leave our neighbourhood without risking seismic panic.
She died five years ago, but I see my mother in everyone lately. On Instagram, my friends' gazes have turned inward: to their food, their dwellings, themselves. And who can blame them? Anxiety and fear are the defining emotions of this historical moment, whipping over the globe faster and freer than wind or electronic money.
A recent study confirms that the actual dangerousness of our lives is decreasing, but our fear of crime is steadily rising. It's the Islamic State, Ebola, illegal immigrants, extreme weather events, IEDs, toxins and terror. It courses through our networks and vaults from our screens to infect our defenseless heads.
How afraid ought one be of bad neighbourhoods or bee-slaughtering pesticides or Russian dirty bombs or slushy ice caps? Who could ever really hope to answer that question?
Reasonable concern is a scarce commodity in our hyperventilated Internet world. Anyone who's stayed up watching the Dopplerized formation of another mega-superstorm that fizzled by morning, or who's begun looking up a minor medical symptom and found themselves self-diagnosing a rare cancer after just 10 minutes of clicking knows what I mean.
And unlike true agoraphobics, we enjoy the fear. Its seduction keeps us clicking and reading and watching. Americans express widespread fear of natural disasters, but few households actually have emergency kits.
What effect does this rising cultural fear bath have? We over-anticipate. Put on our headphones and close our personal borders, lest a stranger engage us in any way. We clutch our phones (which might be increasing our anxiety), read books we're sure we'll like, listen to voices with which we're sure to agree, and sink into isolation as real as my mother's, even if the root of it is different.
Each day we wake up with the realm of safety whittled a little smaller, the borders of our own private domains drawn a little tighter. Outside is disease, bombs, inequality, crime, risk. Inside is warmth, screens, comfort, Amazon packages, plenty, health, safety.
Before her death, through therapy and small acts of daily bravery, my mother was able to hold a job and to drive again. After trips to the grocery store, she would relate enthusiastic stories about all the marvelous people and things she'd encountered. And I think we could all learn a little from her. No matter how isolated and fearful we become, we must stretch our boundaries. We must continue to value bravery and good faith, to aspire to be a people who would rather assume the essentially safety of the world and risk getting hurt, than to live our lives in cowering safety.
We don't have agoraphobia; we should stop acting like we do.
Michael Christie is the author of the novel If I Fall, If I Die.