Story highlights Bipolar disorder affects about 2.6% of the U.S. population

A family history of the disorder makes a person more likely to get it

There is no known cause of bipolar disorder

With the right combination of medications, the symptoms can lessen

Before he got sick, my husband, Mike*, was one of the warmest, funniest guys around. He was a great talker who could engage with anyone about anything -- Czech history one minute, 1950s monster movies the next.

The two of us had countless in-jokes, and our conversations always seemed to devolve into laughter.

But in April 1996, 12 years after we had first started dating, Mike said something that wasn't funny at all.

"See that guy over there?" he whispered to me in a voice so low I had to lean closer to hear. "He thinks I'm CIA." Mike and I had arrived a few hours earlier for our vacation in Saigon, exhausted and bleary-eyed after 22 hours of flying from our home in New York City.

We had eaten dinner and were sipping beers in the café at our hotel. I glanced in the direction Mike was staring. All I saw was a 20-something Vietnamese man reading a magazine.

There was no way that this man thought Mike -- a curly-haired, jeans and T-shirt--clad freelance copy editor -- was in the CIA. Then I looked into Mike's eyes. His pupils were completely dilated. I felt unsteady. Mike just peered at me, his eyes wide with fear.

I could see that something was wrong with him, but I didn't know what. I was naive; mental illness didn't even cross my mind. I simply thought that if we could cut our vacation short and get him back to familiar surroundings in New York, everything would be fine.

But Mike calmed down, insisting that he was OK and that he wanted to stay in Vietnam. I complied, as I often did.

In those days, I was painfully passive, certain that it was best for both of us that Mike made the decisions. And for much of the rest of the trip, I was grateful that we hadn't taken drastic action.

Mike was back to his delightful and charming self. We had pho for lunch one day (a noodle soup pronounced "fuh") and made up puns about it.

"I'd fuh-gotten how tasty this is," Mike said to me, and I laughed.

However, I purposely ignored some of his more curious behaviors: checking the hotel locks and windows multiple times; shushing me, even when we were alone in our room. He had never acted like this before; what I didn't realize was that a new paranoia had taken up residence in Mike's mind -- and it was never going away.

Mike and I met in 1983, when we were college students in New Orleans.

Our relationship turned romantic quickly.

We'd sit in the sun in his quad or mine or read books side by side on his futon, snuggled under his childhood tiger-print blanket.

After graduation, we traveled for a year, strapping on backpacks and bumming around various parts of the world.

Then, in 1987, we moved to Manhattan, where we both got jobs and shared an apartment.

We didn't really have separate lives: We'd often meet for lunch just to catch up on the few hours we'd spent apart. Neither of us went out without the other. If Mike was meeting up with his friends, I'd tag along. If I had a girls' night planned, Mike would come, too.

I was terribly insecure.

I didn't feel smart or clever, and I knew that Mike was smart and clever. So I deferred to him whenever I could. Once I wanted to try a yoga class. So I spent hours convincing Mike to come along. It didn't occur to me that I could try a class on my own. We even shared an e-mail account. It was only years later, as Mike grew ill, that I realized that my dependency was unhealthy.

When we returned home to New York after our trip to Saigon, Mike seemed normal.

But a few months later, when Mike was 33, his strange behavior returned.

At first the changes were subtle.

We had a crate where we kept important papers -- tax forms, passports -- and he became obsessed with rummaging through it.

His voice changed, too, in a way that was imperceptible to anyone but me. His tone was deadened. When he joked, he lacked his previous enthusiasm.

I only began to worry in earnest on the night he stayed out until dawn, without warning.

When he finally came back, he kissed me on the forehead like he'd just finished a day at the office.

Furious, I told him how distraught I'd been. In response, all he said was, "It's OK. I was out for a stroll." Then he shot me an eerie, fake smile.

None of this was like Mike.

I suddenly wondered what else he might do: Would he make an offensive comment to a stranger and trigger a fight? Would he wander into traffic? Increasingly concerned, I called his parents, who lived in New Jersey and didn't know anything had been the matter with their son.

An hour later, they pulled up in front of our building, and we drove straight to the family's primary-care doctor.

He suggested a battery of tests and a hospital stay to rule out physiological explanations for Mike's behavior.

But he clearly suspected mental illness and recommended that Mike go to a psychiatric ward. Shocking though it may seem, that's when it first occurred to me that Mike's mind was the problem. I was both relieved (hey, at least it probably wasn't a brain tumor!) and terrified.

Mike was diagnosed with severe depression and was put on an antidepressant.

But he didn't last long in the psych ward. He checked himself out two days after his arrival, insisting he wasn't sick. And after about a month at home, thanks to medication and weekly therapy, Mike again seemed like himself.

I was so optimistic about his recovery, in fact, that about a year later, when he spontaneously asked me to marry him, I said yes. The next day, December 12, 1997, we took our vows at City Hall.

Five months later, I became pregnant.

I was ecstatic at the prospect of starting a family -- convinced that we would be fantastic parents and that Mike's illness was behind us for good.

But my sense of certainty was crushed just a few minutes after our daughter, Lizzie, was born, on February 9, 1999. As I lay in the hospital bed, Mike leaned over and said, "I heard the baby talk to me."

I couldn't believe it: He had gone off his medication without my realizing it.

I begged him to go back on the drugs, and he listened. But he seemed less stable than before, as though he might lose control at any moment.

As in Saigon, he constantly checked our locks and shushed me. He struggled to bond with Lizzie: He held her in a rocking chair and read her books but often had a totally blank expression on his face.

I never felt comfortable leaving Lizzie alone with Mike. His mind always seemed elsewhere.

When Lizzie was about 14 months old, Mike went off his medication yet again and was hospitalized.

This time he received a new diagnosis, the one he still has today: severe bipolar disorder, which is a mental illness characterized by long periods of depression followed by shorter bouts of mania.

The diagnosis scared me. Although about 5.7 million Americans have bipolar disorder, I'd never known someone with it.

Perhaps for that reason, I saw the disease as shameful. I couldn't bear to tell my mom and dad, or my friends, that Mike was no longer just "depressed."

Meanwhile, Mike wasn't getting better.

Instead of nine good months at a time, he'd have five, then two -- largely because he kept refusing to take his Zyprexa pills, swearing that he wasn't ill.

Panicked, I visited countless doctors, read countless books, and visited support groups in an effort to find him (and myself) real help.

Mike didn't want to hear about any of it. He stopped working and spent hours lying on the floor, listening to "Ziggy Stardust" over and over.

Then one weekend, in the spring of 2002, I reached a tipping point.

Mike was driving the two of us to a nearby grocery store. He seemed a bit withdrawn but still communicative. So I was unprepared when, suddenly, he blew through a stop sign.

I shouted for him to brake, but he didn't seem to hear. "STOP!" I screamed again, petrified, after he ran another. When he finally did stop, I got out of the car and walked home, shaken.

I didn't know what to do. The answer became clear the next day, when our family went to the park. Three-year-old Lizzie held out her hands to Mike, shouting, "Daddy, up!" He just walked right by her, and I saw her face fall.

That night, as I tucked her into bed, she said, "I don't like Daddy really much." Her words got to me. What kind of example was I setting by not putting my daughter first? I made a silent vow to take control of my life.

One day later, I stood before a New York City Supreme Court judge and requested to have Mike committed. I told him, voice quavering, that Mike was a danger to himself and others, citing the stop-sign incident and his inconsistency with his medication as evidence.

The order was granted.

Police officers came to our apartment and took Mike to the hospital; he resisted at first, but eventually the officers convinced him to comply. I told Mike that if he stayed there and got help -- and kept going to his psychiatrist after he was released -- I'd be there for him.

If not, I'd leave. I knew what would happen, and it did: He checked himself out of the hospital after 48 hours (which was legal under the terms of the commitment order).

And true to my word, I took Lizzie and left.

Six months later, I filed for legal separation, and two years after that we divorced.

It wasn't easy: I held on to a lot of guilt for ending the marriage.

I felt that I shouldn't have abandoned someone who was ill, someone whom I had loved for so long. I felt it was my duty to make Mike better.

However, I also was relieved -- for me and for Lizzie.

To her, Mike had been so emotionally absent that his physical disappearance seemed like the next logical step.

As for me, I felt like a great weight had been lifted, and I could finally enjoy life again. I remember walking down the street feeling like I could float away.

After the marriage ended, I needed to talk about Mike's mental illness.

It was as if I'd explode if I didn't. I found I was far from alone.

One friend told me about her debilitating postpartum depression. An acquaintance, who was married with two kids, told me she had bipolar disorder.

But she saw a therapist regularly and understood that she needed medication. Her case made me fully understand the severity of Mike's condition and of his denial.

Seventeen years into his illness, Mike still cycles on and off his medications.

When he's off, he tends to fixate on bizarre ideas. (He's prone to announcing via e-mail that he's an heir to an oil fortune or a Mayflower descendant.)

Mike's mother, with whom I remain close, is his legal guardian and helps him function. He still cannot work.

I've moved on. I married a wonderful man, Jeff, who has been a full parent to Lizzie.

Our relationship is truly equal: We make all our decisions together.

Lizzie and I see Mike only about once a year, due to his erratic behavior. And in between visits we don't keep in touch. I hear about Mike periodically through his mother. Lizzie knows that he has bipolar disorder and that there's a genetic component to the illness.

"Will I get it?" she asked me a few years ago, when she was 11. I told her probably not, but that, regardless, it's usually treatable. We talk openly; I never want her to feel mental illness is something that should be hidden, as I once did.

But I also don't want her to believe that an increased chance of mental illness is the only thing she inherited from Mike.

So I tell her about his keen intelligence, our exciting travelsand the relationship we once shared. And when she laughs and jokes, sometimes I catch a glimpse of that man, my first love. It's a bittersweet moment, but one I wouldn't trade for the world.

The basics of bipolar disorder

Affecting about 2.6% of the United States population, bipolar disorder is a chronic mental illness distinguished by severe mood swings and drastic changes in energy level. Sufferers typically endure long periods of clinical depression, followed by short spells of mania, which can be experienced as euphoria or irritability.

"It's also possible for bipolar people to feel manic and depressed at the same time," says Dr. Igor Galynker, the director of the Family Center for Bipolar Disorder at Beth Israel Hospital, in New York.

Mike suffers from the severest form of the disease, type 1, in which the manic episodes can require hospitalization and feature psychosis (like Mike's delusional thoughts). Type 2 sufferers also require medication, but their symptoms are less dramatic.

What causes it?

There is no known cause, but a family history of the disease makes a person more likely to get it.

"A parent with type 1 or type 2 bipolar has about a 10% chance of having a child who suffers from the illness," says Galynker.

Can it be treated?

With the right combination of mood stabilizers, antidepressants and anti-psychotic medications, the symptoms can lessen, allowing bipolar sufferers, types 1 and 2, to lead relatively normal lives.

Unfortunately many of the drugs have marked side effects (including painful rashes, diabetes, and weight gain), which is why some patients struggle to stick with their regimens. Denial of the illness is another reason.

How can I get help?