In a psychiatric ward in Upper Manhattan, Arvind Sooknanan made a plan for his life. He would drop out of high school, take the G.E.D. test and go on to college, be the first in his family to get a degree.

He was 18 years old, living with a mental illness called schizoaffective disorder, and he had been brought to the hospital after a driver on the George Washington Bridge spotted him trying to jump off. Of all the psych wards he had been through, he told me recently, that one, at Columbia-Presbyterian Hospital, was the nicest.

We were talking in an empty office at Fountain House, whose free “clubhouses” are run for, and partly by, people with serious mental illness. Since that episode on the bridge, Mr. Sooknanan, now 26, had passed the G.E.D. test, earned a college degree and, at the age of 21, run the campaign for the first South Asian woman elected to the New York State Legislature.

He had also become, through Fountain House, a model for what people with serious mental illness can accomplish, and an ambassador to the lawmakers who set mental health care policy. He provides perspective on that homeless person talking to himself on the subway, hearing voices, scaring the other riders. Too many times, he said, he has been that person.

On a recent morning at the organization’s main clubhouse in Midtown Manhattan, he recounted struggles that were hard to reconcile with the figure calmly sharing them: 20 hospitalizations before he was out of his teens; parents who thought he was inhabited by a “spirit”; stints living on the subway or in city parks — and, over and over again, the anguish of being handcuffed by police officers, hospitalized against his will, held for weeks until the doctors cleared him to leave.

“I’m not sure if you can tell,” he said, “but the mental health responses in my life have not been all that great.”