Alissa Dumsch flips through her high school yearbook, pausing on a photo of a hulking young man with sandy hair and a chiseled jaw. “There’s Aaron,” she says, pointing to her brother. “He was so good-looking.” She turns a few more pages. “Here he is at student council. I ran every year — and I lost every year,” she says, laughing. “He ran one year and, like, won by a landslide!”

Dumsch’s parents, Anita and Pat, and her sister, Amanda, have gathered in her home in Scarsdale, N.Y. to share the story of Aaron’s struggle with mental illness.

Pat reaches toward the coffee table and picks up a scrapbook, titled “A Superstar’s Keepsake,” that Alissa made decades ago to commemorate Aaron’s accomplishments in high school.

In 1990s Tucson, where football reigned and quarterbacks were king, Aaron Dumsch looked the part, leading his high school to the state championship.

The Dumsches could tell stories about Aaron’s exploits all day, but there are other tales, too, the kind his family would rather forget. Like the time he shoved a woman with a walker. Or the time he lay on the couch, watching the news coverage on 9/11 and laughing. “We’d lock our bedroom doors because we were afraid he’d come in and hurt us,” Anita says.

Over the past 20 years, Aaron has spiraled from a high school star and an academic all-American on the Arizona State University football team to a ward of the state of Maryland. He has been captive not just to a schizophrenic brain but to a perfect storm of factors — underfunded treatment facilities, prisons and jails serving as de facto asylums, a lack of advancements in medication — that has made it generally harder for people with serious mental illnesses to get the help they need.

All the while, Anita has been at Aaron’s side, trying to care for her son while insulating her family — and the public — from his unpredictable behavior. As she puts it, “Protecting the mentally ill, you become mentally ill just trying to get it all together.”

Wherever the Dumsches landed, Aaron’s athletic talent shone. “He had this really genuine, warm spirit,” says Cara McCrain, a high school friend of Aaron’s. “There was nothing he couldn’t do — in school, in sports, have any girl he wanted. He was it.”

Instead, everything unraveled. Aaron, certain that he’d receive a coveted football scholarship for his senior year, was gutted when it went to someone else. Anita calls that “the turning point,” the moment that “broke his spirit.” That fall, he quit the team. He spent his days smoking marijuana. Soon, he began calling home with strange claims: His dorm room was bugged, or his toes were growing, or the TV was talking to him. “Our initial thought was, ‘Oh dear god, I think he’s on drugs,’ ” Anita says.

Two weeks before graduation in May 2000, Aaron threatened students in an ASU auditorium, raving that he was going to kill them. “I get this phone call. It’s basically, ‘He’s being expelled. You need to come get him,’ ” says Anita. “I get to his dorm room, … and he was totally stoned,” she says. “I was just so mad.”

Aaron moved home. His parents were still convinced he was using drugs, but the truth was more alarming: Aaron was in the midst of his first psychotic break.

“The onset is so cruel,” says Steven Hyman, director of the Stanley Center for Psychiatric Research at the Broad Institute of MIT and Harvard. He’s referring to the fact that schizophrenia typically strikes in the teens and 20s. “Family and society are just finishing their incredible fiscal, emotional, cognitive investment in the production of a wonderful person, and that person is snatched away.”

Fewer than 1% of Americans have schizophrenia, a severe mental illness affecting how a person thinks, feels and acts. Some people hear voices and believe others are plotting against them.

Scientists don’t know exactly what causes it. While some of the risk has to do with genetics, most people with schizophrenia don’t have a first-degree relative with the illness, though many have a family history of psychosis. Environmental factors — such as stress, trauma, maternal malnutrition, and early infection — can play a role.

With effective treatment, some people with schizophrenia lead fulfilling lives, but there is no cure.

“It would be so much easier to say Aaron had brain cancer, because the empathy would be immediate,” Anita says. “When I say, ‘My son is mentally ill with schizophrenia,’ it’s as if I said leprosy.”