Helen and Snowden Chambers' life together started disintegrating 10 years ago. He appeared to be going mad.

Snowden Chambers worked for the United States Information Agency. He was a widely traveled, urbane linguist who knew his way around world capitals. Suddenly, on a trip to Europe, he seemed to lose control.

Chambers was 62 at the time, a man known, among other things, for his phenomenal memory. Inexplicably, he began writing notes to himself, reminders of his son's or his mother's name. In the following months, his behavior became erratic. He wandered off, became lost, forgot how to get home, suffered blackouts, so that hours later he could not account for his whereabouts or what he had done.

Helen Chambers thought perhaps her husband was becoming insane. He was not, although it would be years before she learned that he was suffering from something just as pernicious as madness--Alzheimer's disease, sometimes called premature senility. It is a steady, irreversible, untreatable and ultimately fatal disease that attacks the brain while leaving the body--initially at least--intact.

Snowden Chambers' long and frightening decline is not an isolated misfortune. America's population is growing older. Medical experts expect that unless a cure is found for the age-related disease, Alzheimer's will inevitably become as familiar as today's scourges--heart attacks, strokes and cancer.

In the next 50 years, the over-65 population of this country will grow by more than 150 percent: from about 25 million now to a projected 65 million in 2030. An estimated 4 to 6 percent of all persons over 65 suffer from Alzheimer's disease, which accounts for roughly one-half of all cases of senility, or senile dementia, as geriatricians prefer to call it.

If not checked, Alzheimer's will become a major social and financial burden on American society. By 1990, experts estimate, it could cost as much as $30 billion a year to institutionalize and care for the approximately 1.5 million people who will suffer from Alzheimer's and other forms of senile dementia--the loss or impairment of mental powers.

Unlike cancer or stroke or any other of a number of maladies, Alzheimer's disease usually is not physically debilitating in its early stages. As a result, the victim needs a constant guardian, a "caretaker" in the vocabulary of the disease.

"Constant" means 24 hours a day, since one of the characteristics of the disease is a restlessness that leaves the victim unable to sleep and causes him or her to wander aimlessly. The mind goes first and the body later, leaving an often-incontinent, inanimate stranger inhabiting the body of a beloved father or husband, mother or wife.

For the family of the victim, the disease becomes an almost unbearable ordeal. Bobbi Glaze, the wife of an Alzheimer's victim, described her own experience: "I can tell you that it is like a funeral that never ends. My husband was a handsome, vital, athletic man, a civic leader, a public speaker, a highly respected businessman. He is now a statistic. He is permanently hospitalized, not knowing his family or speaking a word in the past four years. He requires total physical care."

Alzheimer's disease can be even more insidious than cancer. Cancer, according to Dr. Robert Terry, one of the leading researchers of Alzheimer's disease, "kills you, but it doesn't remove your very humanity, your intellect, your personality, your personal habits of hygiene. It doesn't turn you into a vegetable.

"It kills you, fine. We all have to face that. But I don't want to be destroyed as a human. It seems to me that that's the essence of why people were so ashamed for years of mental disease in general. Having cancer or tuberculosis was not sinful. But mental disease is--was. That's because it changes our very soul, our very spirit. It lessens our humanity.

"All diseases are depersonalizing to some extent. But you're still human. You can still respond to pain, anger, to hunger, to whatever and you're still thinking. But a person with a serious dementia is no longer human. He's a vegetable. That's devastating. Fearsome. Terrifying, to anyone who's ever seen it--the thought that that could happen to you."

Snowden Chambers' story is typical of a victim of Alzheimer's disease--his initial ability to hide the symptoms from his family and himself, the seemingly sudden appearance of the problem, and the slow but relentless deterioration of his mind and ability to function.

With the benefit of hindsight, Helen Chambers now thinks she can point to the moment it all began to unravel. Driving to work one day in 1971, her husband suddenly decided that he wanted to retire: "He said to me when he came home in the middle of the afternoon, 'It suddenly occurred to me. What am I doing wasting my life taking risks? Somebody almost hit me. What am I doing out here with these SOBs going to work?' And so he went in and told them and he wanted his papers processed that same day. Now you see, that's unreasonable."

That fall Helen and Snowden Chambers took their trip to Europe, the first time since his retirement that he had broken with the familiar routine of his life. It is often breaks such as these that produce the first signs of bizarre behavior. An energetic, curious man normally, Chambers suddenly showed no interest in leaving his bed to go sightseeing. Several times she went off alone.

During that trip, she recalls, he suddenly became unable to handle simple financial transactions in foreign currency--a failing any ordinary tourist can understand, but a problem Helen Chambers thought strange since her husband was an experienced traveler who had always been more than able to cope in foreign countries.

They returned to America. His personality started to change significantly after his retirement. As an information specialist at the USIA he had prided himself on his facility with the English language, but now he couldn't think of the right word. The memory lapses started. He would go downtown to lunch at Duke Zeibert's or at his club and forget how to get home. He was 62.

"A couple of times," his wife recalls, "he would laugh at night and tell one of my sons or tell me, 'Gee, the funniest thing happened to me today. The last thing I remember I was eating lunch and the next thing I knew, I was driving out toward Laytonsville, and I didn't know where I was for a long time.' And that happened several times. But after a while, he quit telling me about it."

Sometime during this period Snowden Chambers also began writing notes to himself to remind himself who his son and mother were. His son had moved to St. Louis, but Chambers kept calling it Kansas City.

Throughout this period, Helen Chambers says, her husband was becoming hostile. Their relationship, according to her, had been warm and loving. "As he got dimmer intellectually," Helen Chambers recalls, "he thought I was getting smarter. He would tell people, 'Don't ask me about that. Ask my wife. She's the smart one. I'm dumb.' He would say this at parties, and I just thought he was cutting up. When I look back, it was a reflection of his realization that he was diminishing; by contrast, he thought I knew all the answers by that time."

In 1973, Helen Chambers had to quit her job as a librarian at the Atomic Energy Commission. Her husband was hounding her at work, calling her and asking where she was. "I found out later all he had was a telephone number in his pocket." He had forgotten where she worked.

In 1974, he started to refuse to eat with his wife. "He would say things to me like, 'If you're going to be in here, I'm going in another room. I want a divorce. Who needs you?' See, he was feeling threatened, I suppose, and uneasy. I thought he was going through some kind of midlife crisis or something. I was very unhappy about it, but I felt as if he were rejecting me. I find this a very common occurrence in talking to other women. They blame themselves. They think they have done something wrong."

In fact, according to medical experts, what Chambers may have been demonstrating was anger and frustration brought on by physical changes he sensed but could not identify that were loosening his grasp on his life and his world.

Periodically, according to his wife, Chambers would express the desire "to go home." He was in his own house at the time. Physicians, she said, thought her husband was "silly, maybe, or disoriented." None suggested a neurological examination, she said.

In the summer of 1977, when his mother and his wife's mother came to visit, Helen Chambers had to remind her husband who they were, but attributed his failure of memory to the medication he was taking at the time for tuberculosis. Other guests came that summer, and he thought he was in a resort, "and he would complain about why did they keep talking to him," she said. And then he would become lucid again.

During his mother's stay, Chambers got a ride from a neighbor--his wife had by this time taken his car keys away--and went to his bank. He closed their joint bank account, opened a new one and came home uncomprehendingly to show his wife what he had done. His wife immediately canceled the transaction, but then called the family physician to tell him about her husband's strange behavior.

She said the physician told her he had "premature senility," that the physician had noticed it already and that she should have taken her husband to a neurologist already. Chambers, unbeknownst to his wife, had been canceling appointments made by his physician with a neurologist.

Helen Chambers thought her husband was losing his mind.

A neurological examination established that her husband was experiencing "brain atrophy," she said. She was not told anything more definitive, she said.

In September 1977, he became frustrated and angry one day. He started pulling out clothes from a drawer, throwing them away. He put something down the toilet and it overflowed. His wife began cleaning up the mess. He dialed his number on the phone repeatedly, getting a busy signal since he was using the phone.

After an episode like this one, his wife rushed him to a psychiatrist, where he demonstrated more bizarre behavior. When he attacked the psychiatrist, trying to crush his head with a stool, the psychiatrist had Chambers admitted to a hospital. Helen Chambers said she was called early on a Sunday morning by a doctor she had never met and told her husband was suffering from an irreversible and fatal brain disease and that he would have to be put in a nursing home.

That, she said, was how she was told that her husband was dying. From that hospital, Chambers went to a nursing home, she said, but stayed less than three weeks because he became violent. He was transferred in October 1977 to Montgomery General Hospital. That was the last time Snowden Chambers recognized his wife.

From Montgomery General, he went to a state hospital. On Thanksgiving Day, 1977, Helen Chambers brought her husband back to their house in Rockville, where he has been ever since. He has not recognized her clearly once in the more than four years that have passed. In many respects, he is reverting to infancy--rapidly losing his ability to speak, becoming incontinent, changing to an almost entirely liquid diet. Several times he has slipped into a coma and been on the brink of death. Throughout this time, Helen Chambers has nursed her husband, cared for him, loved him. NEXT: The other victim