It was nearing midnight when she slipped out of bed, padded across the wood floors and peered into the room across the hall. Her 15-year-old son was still awake, like she knew he would be, sitting in his bed, staring at his laptop screen. This had long been his nightly ritual: After hours spent playing video games - riveted by a world of guns and gore, adrenaline pumping - he would unwind by watching videos of other gamers playing.
Turn it off, she said.
I need to finish, he said.
No, she said.
Their voices got louder. She doesn't remember exactly what made him reach for the glass on his bedside table. He threw it with such force that it spun across the room and shattered against his closet door, carving a 5cm gash in the white painted wood. Tiny shards glinted on the striped rug.
By then, the family's stately home in New York was riddled with such scars - nicks in the walls, scratches in the floor, a divot in the marble countertop lining the kitchen sink. All remnants of the boy's outbursts, which had intensified over the years, almost always triggered by a simple request from his parents: Byrne, please turn off the game. Please get off the computer.
When Byrne threw the glass, his mother, Robin, didn't panic; she mostly felt numb. For five years, she and her husband, Terrence, had felt their son slipping away - descending deeper and deeper into a realm they didn't like or understand, consumed by the virtual worlds shared by millions of strangers, all reachable through his Xbox and his computer. Robin and Terrence had conferred with therapists, medical experts and school counselors to try to help their son.
Just weeks before, they had turned to an education consultant, who helped them come up with a plan: Byrne had to go away - first, to a summerlong wilderness therapy programme, where he could reconnect with himself and the real world around him, and then to a boarding school. He had to start over, in a place with strict structure, where he couldn't spend his days immersed in video games.
His parents knew it was their last option. If this new plan couldn't save their son, maybe nothing could.
Video games are nothing new, and neither are reports of game addiction. But today's most popular games are wholly immersive: Vast digital landscapes unfold in eye-popping detail, nuanced characters evolve from one level to the next. These games are deliberately designed, with the help of psychology consultants, to make players want to keep playing, and they are available on every platform - gaming consoles, computers, smartphones. Today's teens are more tethered to this technology than any previous generation; these so-called "digital natives" have been playing more sophisticated games at younger ages than their parents ever did.
The games have been criticised as an escape from human interaction, but some offer a different sort of social connection: MMOs - or massively multiplayer online games - allow gamers to play together from any place at any time, and many describe a powerful sense of attachment to those who share this virtual realm. Logging off is that much harder for kids who feel a very real bond to their online friends and teammates.
The result, experts say, is a steep rise in the number of parents worried that their kids are in fact addicted, or at least compulsively devoted, to the games. A residential facility called reSTART, the nation's first therapeutic retreat devoted specifically to Internet addiction, launched a new adolescent programme last month after receiving a barrage of calls from parents desperate to separate their children from video games, consoles, computers and smartphones. A small but growing number of psychologists across the United States have begun to specialise in treating children who struggle with compulsive gaming and screen use.
"I don't think we know exactly how many are suffering from this, but we know it's a big problem," said psychologist Kimberly Young, founder of the Center for Internet Addiction. "A modest estimate might be 5 per cent. But 5 per cent of American kids is a lot."
Boys tend to be more susceptible to compulsive gaming than girls, but any kid who is trying to avoid overwhelming stress - bullies at school, a difficult home environment, social anxiety - might be especially drawn to video games. Experts also see a correlation between obsessive video game use and traits associated with autism, attention deficit disorders, anxiety and depression, although the exact nature of the connection is not fully understood.
Whatever the causes behind this unhealthy attachment, at least one common factor comes through, said Kim McDaniel, a therapist and parent coach who specialises in the compulsive use of electronics.
"The biggest impression I get," she said, "is that we have this generation of teens and kids who are just so lonely."
Terrence and Robin say they were never the kind of parents who parked their children in front of the TV or relied on computer games and electronic gadgets to keep them occupied. Terrence, a pragmatic government employee, and Robin, an artistic owner of a small business, made it a priority to spend uninterrupted time with their two boys. They read books with Byrne and his brother, who is three years older, every day. The family cooked meals together and often took long outdoor walks.
The couple revisited their memories of Byrne's childhood on a recent November evening, sitting together at their dining room table in the 1920s-era house where Byrne and his older brother grew up, nestled behind a row of tall pines on a quiet, small-town street. They both spoke thoughtfully, often completing each other's sentences. They asked that their family be identified using middle names to protect their privacy.
The first signs of Byrne's anxious and obsessive behavior surfaced at 4, when he would agonise over which book to read at bedtime: "It had to be the just right book," Robin recalled. In first grade, he excitedly brought his class roster home and called his classmates over and over to set up play dates, with such persistence that the families on the other end of the line rarely obliged.
Byrne was 6 when he first saw a therapist. At 10, he was hospitalised in a pediatric psychiatric unit; doctors told his parents that their highly intelligent, highly sensitive son had severe anxiety. Soon after, his therapist diagnosed him with ADD.
Byrne had trouble making friends, partly because of his obsessive behaviour, partly because of his strong personal convictions. In fourth grade, when Byrne heard a couple of classmates complain that the school's celebration of Black History Month was unnecessary, he launched into a passionate and eloquent rebuke. His teachers were impressed; his peers shunned him even more.
It was around that time when a relative gave Byrne and his brother an Xbox. Gaming was deemed a privilege Byrne would lose if he misbehaved. But that structure soon proved hard to implement.
"He was relentless about asking when he could play - it was a continuous negotiation," Robin said. The routine grew exhausting, she added, and sometimes she and Terrence caved in to Byrne's demands. "The games were his refuge."
The pattern worsened after Byrne entered middle school.
"In seventh grade the downward spiral began, after having maintained High Honor Roll for one quarter, I was given a laptop. This is when my addiction to screens began."
Byrne wrote these words years later as part of a reflective essay assignment while he was away at the wilderness therapy programme.
"In eighth grade, my grades continued to be high, but my parents began to notice my addiction to xbox and my laptop worsening."
Byrne had frequent arguments with his brother, who had once enjoyed playing games with him, and the two began to spend less time together. One by one, Byrne quit the sports teams that he'd once loved - football, baseball, basketball, lacrosse, sailing. He protested whenever his family made plans to leave the house.
"Anything other than video games," Robin said, "he called 'a waste of time.' "
At the height of his obsession, Byrne's games of choice were from the Call of Duty: Modern Warfare series - first-person shooter games that are every bit as absorbing and nerve-racking as a real military battle simulation or an action movie, replete with stunning graphics, sound effects and atmospheric theme music. The gamer becomes the soldier: Leaves crunch beneath his combat boots as he stalks through an open field, gun raised. There is the sound of a thumping heartbeat when an enemy guard appears in the crosshairs, the soft ping of the bullet firing, a sharp inhalation of breath and a burst of dark blood as the guard falls.
Every movement, every shot fired, every victory within the game is accompanied by real-life physical and neurological responses: The gamer's muscles tighten, the pulse pounds, and the brain's prefrontal cortex - its pleasure centre - is activated.
Researchers are still trying to figure out exactly how and why video games affect the brain. One 1998 study showed that video games raise the level of dopamine in the brain by about 100 per cent, roughly the same increase triggered by sex. (And that was nearly 20 years ago - today's games have evolved far beyond what was available then.) More recent research found measurable changes in the parts of the brain linked to cognitive function and emotional control after study subjects spent one week playing violent video games.
After Byrne's prolonged periods of play, his parents noticed that his temperament was unusually volatile. The muscles in his back and neck felt tense and tight. His eyes would sometimes twitch. Lines of dialogue from the games would pop into his mind unbidden. At school, the class dismissal bell occasionally sounded just like the two-tone chime that signaled a new friend joining a game online - a sort of auditory hallucination that researchers refer to as Game Transfer Phenomena (GTP), in which the boundaries between reality and the game begin to blur.
Nicholas Kardaras, a New York psychotherapist and author who specialises in addiction, still remembers the very first gamer he treated who suffered from GTP: a teenage boy in a Metallica T-shirt who appeared frightened and confused as he sat in Kardaras's office.
The boy blinked, looking up at the ceiling, then down at the floor.
"Do you know where you are?" the psychotherapist asked him.
The boy was quiet for a moment. Then he asked: "Are we still in the game?"
"When ninth grade rolled around, I began to ignore my responsibilities as a student for screens. I began to [make] more friends, however I did not notice that these people were making fun of me nonstop."
Byrne's classmates only really hung out with him through video games - each in their separate homes, connected online and through headsets that allowed them to chat while they played. But the same social hierarchy followed Byrne from his school hallways into the games, where the other boys continued to tease him.
Byrne tried to laugh it off; being mocked still seemed better than being ignored altogether. His parents noticed that he was often upset when the games ended. But he insisted on going back, because he felt he had nowhere else to go.
When Byrne started failing classes and refusing to go to school in 10th grade, his parents knew their situation had grown dire. They hired the education consultant who urged them to enroll Byrne in a private boarding school. The thought of sending him away was wrenching - but also hopeful.
"Finally, we had a path," Terrence said. "We just had to figure out how to pay for it."
Because video-game addiction isn't recognised as an official diagnosis by the guidebook of American psychiatry, the Diagnostic and Statistical Manual of Mental Disorders - which cites "Internet Gaming Disorder" as a condition warranting more research - medical insurance doesn't cover treatment, which can quickly climb into the tens of thousands.
Byrne's parents said they took out a second mortgage on their home, raided their savings, ran up their credit cards and applied for financial aid to help cover the US$25,000 summer-long therapy programme and the annual US$50,000 private school tuition.
"We knew, if we do this, and it doesn't work, then we know we've done everything," Robin said. "And you will do anything for your kid."
Byrne wanted to go to the boarding school; he was eager to get away, to start over. He was less thrilled about the wilderness programme but understood that it was mandatory. When his family dropped him off for 10 weeks in Vermont in June 2015, he handed over his phone and said goodbye.
His parents returned to a quiet house, filled with memories of a painful past that they wanted to leave behind. So Robin gathered years' worth of files - towering stacks of teachers' reports, special education plans, insurance forms and her own notes - and carried them into the sunny living room. She knelt beside the brick-lined fireplace and struck a match. Then she fed the papers to the flames, watching as they withered and crumbled to ash.
Byrne is 17 now, a sweet-natured, soft-spoken kid with glasses and a mop of tousled brown hair. He speaks with his father's baritone voice and his mother's thoughtful eloquence.
He lives on a sloping, wooded campus in New England, where his days are filled with classes and organised outings. Now in his junior year - he had to repeat 10th grade - he earns mostly A's and B's. He has a circle of friends and a roommate he describes as "hilarious" and "compassionate." On Saturdays, Byrne goes sailing with the school team. On Sundays, he does his homework and orders pizza for dinner with his friends.
And, once or twice a week, he allows himself to play video games. This concerns his parents; they worry that his struggle to distance himself from the games isn't over, that the risk of relapse always looms.
Byrne feels he has a healthier relationship to the games now. "I have to do my work, then I can play," he said. "It's much more like, 'I can do this for a treat.' " But he knows he'll always have to monitor himself carefully. He wants to go to college to become a counselor, to help other kids who are struggling like he has. He is repairing his relationship with his big brother, who began to drift away from Byrne when he became consumed by the games.
Lately, he's been into a game called Overwatch, a multiplayer first-person shooter game made by the creators of World of Warcraft, the most lucrative online video game in history. Set in a future version of Earth, Overwatch has an intricate story line and a cast of "heroes," each with different skills and detailed biographies. Byrne plays the game with online friends and has become close to many of them: "Everyone likes me there," he said.
He plays at his desk in the corner of his dorm room, a bright, messy space strewn with shoes and laundry and smelling faintly of microwave popcorn and gym socks. On a recent Sunday afternoon, he settled into his chair and opened his laptop, a model specifically designed for gameplay.
The screen was a blur of chaotic motion as his character stormed from one level to the next, through bright streets and towering canyons and apocalyptic underworlds. The illuminated keyboard bathed Byrne's fingers in rainbow-colored lights. The speakers blasted the sounds of grunts, gunfire and shouts.
The world is worth fighting for! said the character he'd chosen for the game, a nerdy but powerful female scientist named Mei. Byrne smiled. "That's one of the lines that pops into my mind sometimes," he said, and repeated it as his right hand furiously clicked the mouse.
"The world is worth fighting for."
Outside the tall windows, the day faded to late afternoon, the shadows of trees lengthening over the yellowed grass. Soon it was four o'clock, and Byrne had been playing for several hours. The guys would be ordering pizza soon, before evening study hall. Byrne had final exams to prepare for.
The sound of his friends' laughter echoed in the hallway.
On the computer, a countdown ticked: Next game starts in 20 seconds ... 19 ... 18 ...
His hand moved across the glowing keyboard, and with a soft click, the world on the screen disappeared.