If you were to encounter my son, Tim, a tall, gaunt man in ragged clothes, on a San Francisco street, you might step away from him. His clothes, his dark unshaven face and his wild curly hair stamp him as the stereotype of the chronically mentally ill street person.

People are afraid of what they see when they glance at Tim. Policymakers pass ordinances to keep people who look like him at arm’s length. But when you look just a little more closely, what you find is a young man with a sly smile, quick wit and an inquisitive mind who — when he’s healthy — bears a striking resemblance to the youthful Muhammad Ali.

Tim is homeless. But when he was a toddler, my colleagues in the Connecticut state legislature couldn’t get enough of cuddling him. Yet it’s the policies of my generation of policymakers that put that formerly adorable toddler — now a troubled 6-foot-5 adult — on the street. And unless something changes, the policies of today’s generation of policymakers will keep him there.

During the 25 years since, I’ve experienced firsthand the devastating consequences of these mistakes.

Every year, one in every five children and one in every four adults has a diagnosable mental illness. A quarter of all mental illnesses are considered serious. Until Tim came into my life in 1985, I had no experience with mental illness in my immediate family.

Problems in kindergarten

As with many other chronic diseases, the symptoms of mental illness often sneak up slowly. Beginning in kindergarten, Tim had persistent problems making friends, keeping his focus and following directions. He was usually gentle. But he also had a scarily short fuse. He slept poorly at night and reported that he “got yelled at a lot” in school.

I can’t point to a single time when I first realized Tim’s problems were not just normal. The day he lay down in the middle of the road — just to see if a car would run him over — comes to mind, however.

Tim’s mental illness turned out to be a serious one — schizophrenia — but the disease wasn’t diagnosed until he was 17, after he’d been sick for more than a decade. That’s pretty much the norm for serious mental illness: Typically, 10 years pass from the time people show symptoms of mental illness to the time they receive appropriate treatment.

When Tim entered elementary school, it took us three years to convince school officials that his symptoms weren’t caused by problems with Tim’s having been adopted, his racial identity (we’re white, he’s black) or our parenting. That by then we had three children younger than Tim who also were adopted transracially and were thriving helped make our case. The school’s evaluations suggested he had what was then called attention deficit disorder and some learning disabilities. He was admitted into special education, and the school drew up a mandated individualized education plan (IEP) for him. It focused mostly on helping with his organizational skills and, at the school’s insistence, his “self-esteem.”