More than 2 million Americans suffer the severe mood swings of bipolar disorder, but no one can express its seriousness quite like a 30-year-old Chicago woman did last year.

"I was never quite honest about how often I was miserable," she wrote in her suicide note, "which was pretty much all the time."

Her feelings reverberated yesterday when her note was read by Lydia Lewis, president of the Depression and Bipolar Support Alliance, as the Sixth International Conference on Bipolar Disorder convened here.

Though the disorder is a leading cause of disability, little progress has been made in developing better ways to fight the disease, said Dr. Thomas Insel, director of the National Institute of Mental Health.

In the 1980s and '90s, advances in research "really languished," Insel told about 1,100 physicians, other health professionals and advocates gathered at the David L. Lawrence Convention Center, Downtown.

Besides having a greater risk for suicide, many people with the disorder also grapple with anxiety, eating disorders, substance abuse or other health problems.

Among the findings reported yesterday, Dr. Marion Leboyer of the University of Paris noted that immediate family members of patients with early onset bipolar disorder were at greater risk for developing the disease.

A researcher from the Netherlands, Dr. Willem Nolen, found that bipolar patients were twice as likely to develop autoimmune thyroiditis, a thyroid disorder. If confirmed in later studies, the research suggests that a test for that condition might help to identify people at risk for bipolar disorder.

Still, Dr. J. Raymond DePaulo, director of psychiatry at Johns Hopkins University, said genetics currently has provided few clues about treatment of bipolar disorder.

Ideally, the physiology of the disorder should drive the development of drug therapies, Insel said, noting that improved methods of analyzing the human genome may help to speed that process.

But for decades, he said, therapies have developed mostly because they appear to work or are similar to other drugs that have been successful.

Many treatments "are simply by trial and error," he said, "and we don't know what treatment is best for each person."

About one-third of bipolar patients can be successfully treated on one drug, said Dr. Michael Thase, a psychiatrist at the University of Pittsburgh School of Medicine. But, he said, most are on four or five, in part because of the need to get patients who relapse out of the hospital as soon as possible.

Many patients, too, are not promptly diagnosed, he said, often waiting for years and seeing several doctors before their condition is detected.

Noting the suffering and huge costs to the public mental health system caused by the disorder, Insel advocated an improved approach. Most needed, he said, are better methods of diagnosis, treatment and prevention and of delivering optimum care to people most in need, many of them homeless or in prisons or jails.

But he acknowledged that the nation's research spending on mental disorders is relatively meager: about $1.4 billion annually, or less than $5 per person.

"We need a lot of money to do what he's saying we need to do," Lewis said.

The conference, sponsored by the Pitt medical school and Western Psychiatric Institute and Clinic, continues through tomorrow.