Bipolar patients can spend one-third of their lives in a manic state.(MIKA/ZEFA/CORBIS)

To understand bipolar disorder, think of a pendulum. People with this disease swing between episodes of depression and periods of mania.

Glenn Koons, 50, of Reading, Penn., says when he was depressed, "I totally turned inward." But when he swung into a manic phase, "You start thinking you are invincible. And in the work world, it can have a positive side, but then it spins out of control."

Steven D. Hollon, PhD, professor of psychology at Vanderbilt University in Nashville, says that manic bipolar patients can destroy their own families. "Manias are like a mildly controlled cocaine high," he says.

In full-blown mania, people may hallucinate or lose touch with reality.

Three categories of bipolar disorder exist.

  • Bipolar disorder I is the classic type. People have depression, get better for a time, then go into a manic episode.
  • Bipolar disorder II is similar. People have episodes of depression, but the manic phases aren't as serious or destructive as in bipolar I. For example, instead of being grandiose or delusional, the person may be extremely self-confident, cocky, or ambitious. These milder manic episodes are also called hypomania. In addition, people with bipolar II tend to have fewer manic episodes than people with bipolar I.
  • The third type of bipolar disorder is called the rapid-cycling form. People with this type have four or more episodes of depression and/or mania in a 12-month period. They may be healthy between episodes of depression and mania, or they may go directly from depression to a manic episode.

It's crucial to tell your doctor if you've had mania in the past, even if you're very depressed right now. And be fussy about the doctors you see. "The diagnosis of bipolar depression should be made by an expert because it has important implications for treatment," says Walter Brown, MD, clinical professor of psychiatry at Brown University and Tufts University School of Medicine.

[ pagebreak ]The wrong diagnosis can trigger mania
That means that you should see a psychiatrist rather than an internist or family physician to get the correct diagnosis. The immediate danger is that if you are misdiagnosed with major depression but actually have bipolar disorder, you'll be given an antidepressant. In people with bipolar disorder, treatment with an antidepressant alone can trigger a dangerous bout of mania.

In addition, a bout of severe mania can be mistaken for schizophrenia. The drugs used to treat schizophrenia are not the same ones used to treat bipolar disorder.

But diagnosing bipolar can be tricky even for experts. If people had equal numbers of depressive and manic episodes, the diagnosis would be a snap—almost. But most people with bipolar disorder spend much more time depressed than they do manic.

Depression versus manic symptoms
When they're ill, people with "classic" bipolar I are depressed about 67% of the time, mixed/cycling about 15% of the time, and manic about 18% of the time, says Michael Thase, MD, professor of psychiatry at the University of Pennsylvania. People with bipolar II are depressed about 90% of the time that they're ill, he adds.

Most people have several bouts of depression before they have any sign of mania, explains John Markowitz, MD, a research psychiatrist at the New York State Psychiatric Institute and clinical professor of psychiatry at Weill Medical College of Cornell University. As a result, these people get an initial diagnosis of depression. "People are sometimes diagnosed with major depression simply because they can't be correctly diagnosed with bipolar disorder yet," says Dr. Thase. This is a problem if the misdiagnosis of major depression is accompanied by a prescription for an antidepressant. People with bipolar disorder generally should not take antidepressants unless they also take another type of drug called a mood stabilizer.