My brother Tom’s slide into homelessness occurred in stages. We never knew exactly when or how he lost his apartment, or came to crash on friends’ couches, or began having run-ins with the cops. Nor did we mark the beginning of his habit of walking incessantly, roaming the streets and bike paths of Anchorage, Alaska, our home town, as he would for the rest of his life. Friends and family members told me, much later, that he had been spending whole days driving around the city, marking up a map with notes and arrows, pursuing a delusion about women whom he believed had been kidnapped. Once, wandering and mumbling, he was picked up by police and later told a doctor that he had been fleeing the sensation that he was “about to hear the sound of a woman scream.” Another time, when our father wasn’t home, he apparently jimmied the lock with a credit card and grabbed an old checkbook for a closed account. Then he used it to book a room at a quaint little inn downtown and to make various other purchases: collectors’ coins, geodes, a framed painting, a Persian rug, and heart-shaped pendants for some secret or imagined love.

If you Google “How to convince someone with schizophrenia to get treatment,” you discover a vast network of distraught families grappling for answers. When met with resistance by a person in the grip of psychosis, experts advise, try to work around rigid beliefs rather than attempting to dismantle them. Don’t argue with delusions, and don’t focus on points of contention. Listen respectfully and empathize. On the message boards at Schizophrenia.com, people weigh the merits and dangers of coercion, even its harshest forms. A man with schizophrenia expresses gratitude that his parents never kicked him out when he refused treatment, saying that he would not have got better without their unwavering support. Another states that, if he hadn’t been kicked out, he would never have sought help. Although research suggests that the gentler, subtler forms of pressure may be more effective, it seems that nothing works for everybody and everything works for somebody.

Long before Tom began exhibiting symptoms, in his twenties, our family was familiar with these dilemmas. When I was ten years old and Tom was seven, our mother began showing signs of serious mental illness. Formerly bright and spritely, she, in the grip of illness, neglected herself to the point of malnourishment and became certain that most members of our family were doubles replacing the people she knew. I spent my adolescence watching her deteriorate. Doctors believed that she had some form of schizophrenia, but she maintained that she had no mental illness and refused medication, as she has ever since. When those of us with less spectacular minds attempt to imagine the inner experience of someone like my mother or my brother, we usually fall short. We fail to grasp the deep changes that accompany psychosis—radical shifts in how the mind relates to both the world and the self.

For a time, Tom lived with our father in Anchorage, but he fought Dad’s attempts to keep him on his medication. The fights steadily grew worse, culminating one day when Tom left and did not return. He was soon arrested again, and, when he was released, Dad told him that he could not return home while he remained unmedicated. I was told later that Tom told a friend he had quit his antipsychotic drug because taking it made him feel “embarrassed”—embarrassed by his circumstances, by his diagnosis, by the unravelled state of his life.

Over time, my father, my two sisters, and I considered and discarded various other ideas. Could we get him an apartment? He’d leave something on the stove and burn the place down. What about hiring a personal caregiver? An employee couldn’t be there twenty-four hours a day. What about the Alaska Psychiatric Institute? The A.P.I. didn’t have enough beds to meet demand, so it pushed patients out as quickly as possible. What about a private psychiatric hospital, someplace he could stay longer? There were none in Alaska. What about moving him to a hospital outside of Alaska? We couldn’t force him to stay there, and, once he left, he could go anywhere. We’d never see him again.

So Tom remained on the streets, in the cold of an Alaskan winter. I was living far away, in Santa Fe, unable to do much to help, and I came to rely, for consolation, on certain things that I knew about my brother. He had been a skier, a camper, a mountain climber. He was strong and fit, with a wide-ranging intellect and a practical mind, and, in his early twenties, when he was still a student at the University of Colorado, he had done things like bike through Europe and climb a forbidding Alaskan mountain called the Moose’s Tooth. I knew he had the skills to survive outside, to make a camp in the woods—as long as he could keep track of his gear and find enough food. That was my biggest worry at first—that he was always hungry. Nights, I tried not to imagine the worst possibilities. Instead, I placed him in the safest, warmest camp I could conjure. I led him into the thickets beside the Coastal Trail, built him a snow cave, stuffed him into a fat sleeping bag on a thick foam pad, filled his pack with dry gloves and long underwear, and placed new socks on his feet.

Dad took to scanning the Anchorage Daily News for bits about homeless men, reading closely when a body was found in Chester Creek or Kincaid Park. He stopped taking trips during the winter, wanting to be home to answer the door if Tom stopped by on a cold night. There could be no Christmases, no Thanksgivings, no New Year’s Eves without the wondering.

People helped. A teacher from our high school drew Tom indoors with a ruse: he said he needed someone to read aloud to, picked up “Moby-Dick,” and kept Tom listening as long as possible. A friend’s parents left the door to their vestibule unlocked when they were away, so that he could stop there and warm up. Friends would say they ran into him at the library, or they passed him in their cars. He was standing in the rain. He was in the parking lot beside Westchester Lagoon, staring into space. They cooked him dinner or gave him a few bucks or let him take a shower. They were our surrogates and our saviors, feeding him, keeping him company, keeping him warm.

In 2009, nearly three years into Tom’s homelessness, I made it back to Alaska. It was June, the lightest time of year. Flying in on a clear evening, I got a view of the southern mountains, tangles of peaks and glaciers walling off the city. My goal was to glimpse a way to get through to Tom, to spot an opening to convince him to come inside and get help. I put word out to friends that, if anyone spotted him, I’d like to know. For two days, I did little more than drive around, scanning the sidewalks. It made me feel a little insane, the acute sense of his nearness, the chance that I might drive right past him without noticing.