The hysterical young girl was taken to a hospital, where she was diagnosed with bipolar disorder. Sidney was sent, barefoot, to a neighbor's house.

"For a long time, no one really explained what was wrong with her, " said Sidney, now 50. "All I knew was she was always vicious to me.

"Once she caught me in her room looking at her books, and she beat the hell out of me. If I got a new toy, she'd tear it apart. ... The one time I had a tantrum about how mean she was, my mother screamed, If I have two crazy children, I'll kill myself!' So from that day on, I was the perfect son. "

If Sidney's tale had a familiar ring to author Victoria Secunda, it's no coincidence. Her own sister -- a bright, professional woman she calls Deborah -- had been ravaged by psychosis as a young adult, leaving Secunda shaken and filled with questions such as: Why her and not me?

"We came from a family where there were very high standards and enormous demands, " said Secunda, author of "When Madness Comes Home: Help and Hope for the Children, Siblings and Partners of the Mentally Ill. "

"In my case, I became merely neurotic and hugely anxious. "

She also became a sympathetic ear to more than 100 forgotten victims of mental disorder -- the siblings, partners and other close relatives of often difficult and demanding patients.

Sidney and others -- their identities disguised -- spoke of lost childhoods, a stunted ability to distinguish normal from not, and an unspoken fear that they'd be the next to crack.

"These kids are anything but OK, " Secunda said. "They dare not gripe about things that are important to them. These kids need help; they're the also-rans. "

Secunda said children suffer just as much in families rocked by more common disorders, such as depression. In fact, according to one study, depressed patients are nine times more likely to be divorced than the general population.

Lifting the lid

One of every five families is affected by serious mental illness in their lifetimes, says the National Alliance for the Mentally Ill (NAMI), a nonprofit support and advocacy organization of families, friends and people suffering from severe mental illness.

For those who have grown up with it, a burden is borne that is not often discussed. But they are stricken as surely as the manic depressive or the schizophrenic.

"There's a sense of lost childhood, a grief and a loss at the core of their experience, " says Diane Marsh, a psychologist who teaches at the University of Pittsburgh at Greensburg and who's done research about mental illness and families.

Mental illness "drains off the energy needed for a child's normal development. They're often forced into parentified roles before they've finished being children, " says Marsh, whose book, "Troubled Journey: Coming to Terms with the Mental Illness of a Sibling or Parent, " came out over the summer.

For a child with a mentally ill parent, "it's hard later to put your trust in people because the person you trusted most -- your mother or father -- could go away repeatedly. Go away by being sent to the hospital or by talking nonstop and not paying attention to you. These children have great difficulty with intimacy later on, " says Secunda, sister of a paranoid schizophrenic, daughter of an alcoholic.

She adds that, for a child or sibling, "there is no concept of normality. You learn the outside world by rote. You're afraid to lose control, afraid that if I start crying, will I ever stop? Am I chronically depressed, too? "

The price of silence

It is not easy to define.

"Mental illnesses are biologically based brain disorders that profoundly disrupt a person's ability to think, feel, relate to others and their environment, " is offered by NAMI, which is based in Arlington, Va., and has chapters across the country.

That definition fixes the cause as a genetic or chemical disorder, blame that can be tossed into a biological box. But, as Secunda writes, it's likely to be more complicated:

"The professional consensus is that these disorders are biologically based vulnerabilities that can be triggered or induced in a variety of ways by such environmental stressors such as financial or marital troubles. "

Secunda said she believes the lingering stigma of mental illness explains why only 20 percent to 40 percent of Americans with psychiatric disorders get treatment.

"If you call it a mental illness, people think, God -- Norman Bates!' " she said.

Yet, by her reckoning, an estimated 100 million Americans have a close relative who has suffered from a mental disorder, including anxiety, depression and drug abuse, which can be a form of self-medication for undiagnosed mental illness. She and Marsh say the good news is that mental illness has a higher treatment success rate -- 60 percent to 80 percent -- than does, say, heart disease, at 41 percent to 52 percent.

"Having a diagnosis is not the end of the world, " said Secunda, who takes anti-anxiety medication in front of her book-talk audiences to help de-stigmatize the issue. "Having no one to talk to (about it) is the end of the world. I have found through many years of therapy that to tell all is the way to go. "

Secunda speculates that greater openness might have helped writer Michael Dorris, whose suicide in a New Hampshire motel room earlier this year broke the silence on the crippling depression that eroded his marriage with novelist Louise Erdrich. Dorris' closest friends expressed shock at learning of his depression, but Erdrich told a reporter, "I knew that Michael was suicidal from the second year of our marriage. "

That's a heavy load for any wife to carry.

"Had they talked about it, had they written about it, " Secunda said, "she would not have had to carry that burden alone. "

As traumatized bystanders to severe mental illness, children and siblings face lifelong issues, including the realistic worry that a caretaker role looms in their future.

Secunda found that the legacy of disrupted childhoods colored all aspects of her subjects' lives. More than half worked in the arts, where they could figuratively cry out for attention, or in the helping professions, where they could search for answers and assuage their guilt at being well.

Despite their mistrust of a mental health system that seemingly failed them, three-quarters eventually sought therapy. And -- finding cold comfort in statistics that strongly favor their chance of having normal children -- more than half decided to forgo parenthood.

One woman whose father was schizophrenic decided not to tempt fate after she married a man whose parents were both alcoholic and diabetic.

"The sick joke in our house, " she said, "is that if we had kids, they'd all become alcoholic, insulin-dependent schizophrenics. So we raise horses instead. "

Working things out Laurie Flynn, executive director of the National Alliance for the Mentally Ill, told Secunda she was keenly aware of the potential impact on her other children when her 18-year-old daughter -- the class valedictorian -- was diagnosed with schizoaffective disorder, which has some of the features of schizophrenia and affective, or mood, disorders.

"I never wanted my other children to feel they had a special obligation to their ill sister, " Flynn said. "It's important for them to have their own lives. "

Secunda praises celebrities such as Mike Wallace, Art Buchwald and Patty Duke for spreading hope and understanding by acknowledging their treatment for mental disorders.

While disclosure often carries a risk, it has been a boon to "Shine " pianist David Helfgott, who has forged a new career by publicly triumphing over schizoaffective disorder, even in the face of dismal musical reviews from critics.

Secunda cites an even more inspiring example -- Fred Frese, director of
psychology at Western Reserve Psychiatric Hospital in Ohio, who went on to earn a doctorate, marry and raise four children after being diagnosed with paranoid schizophrenia.

"What seemed to make such relationships work is that everyone including children, in the family talked about what was going on, " Secunda said.

She calls Frese a hilarious and charismatic man who draws standing-room-only audiences at his talks to CNPs, or Chronically Normal Persons. He's vigilant about his symptoms, carries extra medication and accommodates the ultra-sensitivity his illness induces by handing out a card explaining his condition.

"When I am berated, belittled, insulted or otherwise treated in an oppressive manner, " it reads, "I tend to become emotionally ill. Could I ask you to restate your concern in a manner that tends not to disable me. "

Talk -- and talk is less promising when mental disorders remain secret < and untreated. Children of the mentally ill are at special risk, according to the American Academy of Child & Adolescent Psychiatry, not only because their genes may tilt them toward psychiatric problems, but because they may lack a consistent, loving environment.

"Unfortunately, " the academy says, "families, professionals and society often pay most attention to the mentally ill parent and ignore the children in the family. "

Siblings of mental patients face even tougher challenges than parents, according to Eleanor Owen, executive director of Washington Advocates for the Mentally Ill, who has experienced both roles -- sibling and parent -- and counseled thousands of families.

"After a period of time, parents resolve any residual guilt they may have felt," Owen said, "but my observation is siblings never do. There's a sibling bond that's very different than any other relationship people have. " Secunda, 58, paints a harrowing portrait of the breakdown of her own half-sister, Deborah -- the wise big sis who taught her how to navigate life's milestones, from the senior prom to the scary abyss of college
graduation.

As an overburdened child, Deborah was the stoic peacemaker in a wildly dysfunctional family marked by alcoholism, multiple marriages and incest. Secunda believes Deborah's illness, which probably had a genetic component, was a kind of sanctuary for her.

Fortunately, Deborah recovered enough later in life to hold her symptoms in check and return to work, although she sometimes needed to increase her medication or take medical leaves.

The future take medical leaves.

The scenario in workplaces across America as employers fall in line with the Americans with Disabilities Act, which requires employers to provide reasonable accommodation to workers with mental as well as physical disabilities. Secunda said that wasn't a problem for Deborah's employers, who "loved her and treasured her talents. " Sadly, Deborah died of cancer before Secunda's book came out.

As Secunda gathered anecdotes for her book, she also compiled a wish list from those she interviewed. Improved access to mental health care is the top priority for many siblings and offspring, who also want more safeguards for their own protection against dangerous relatives who don't meet the legal test for forced commitment.

They also said they'd like a larger role as consultants on treatment and public policy. And they pleaded for more collaboration among researchers warring over biological vs. environmental theories of mental disorder.

Most of all, family members want to be heard. Secunda says she hopes her book brings comfort to relatives who feel that no one will listen, that they have nowhere to turn.

"They are not, and need not be, alone, " she says.

For More information on Victoria Secunda's book - and other recommended books on this topic, see:

Books for Brothers and Sisters, and Sons and Daughters of people with Schizophrenia