MINNEAPOLIS (WCCO) — In this week’s People magazine, Mariah Carey opens up about her struggles with bipolar disorder. The singer said she was first diagnosed in 2001 but only recently sought treatment. She said she hopes talking about it will reduce the stigma.

So, what exactly is bipolar disorder? Good Question.

According to the National Institute of Mental Health, 4.4 percent of American adults have experienced bipolar disorder at some point in their lives.

“Bipolar disorder is a serious, major mood condition that consists of a couple different types of mood states,” says Dr. Kaz Nelson, professor of psychiatry at the University of Minnesota Medical School.

In the past, bipolar disorder was called manic-depression. It plays out with dramatic changes in moods, energy and activity that are more severe than everyday mood swings.

Dr. Nelson says people can have one state called mania, where they feel better than they ever had, have more energy, talk fast, make plans and sometimes have delusions. That state alternates with severe bouts of depression, where people don’t do things they like, have low energy and feel sad or hopeless.

These states can last for days or weeks.

Researchers have found some genetic and stress links, but don’t know exactly why some people have bipolar disorder and others don’t.

“We do know their brains are different, but we don’t know exactly how,” says Dr. Nelson.

There are generally two types of bipolar disorder. Type I has very high highs and very low lows. According to the National Alliance on Mental Illness, Type I is an illness where a person has experience one or more episodes of mania. Type II, the kind Mariah Carey says she has, carries the same kind of depressive state, but less severe mania.

Right now, there are no blood tests or brain scans used to diagnose bipolar disorder. Doctors have to listen to the patient’s story over time and often talk with family members about behavior.

“It can be hard to diagnose if we’re just seeing somebody at one point in time,” says Dr. Nelson. “We have to do a little detective work, questioning and take a very thorough history asking if there is a period where someone has been more productive than usual.”

Bipolar disorder is generally treated with mood-stabilizing drugs, more consistent schedules and therapy.

In a 2009 interview with PBS, Jane Pauley discussed her bipolar disorder diagnosis. She says she now watches her sleep very carefully.

“Nobody is immune from being diagnosed with bipolar disorder,” says Dr. Nelson, “People can actually be highly functional with bipolar disorder if it’s properly treated.”

Heather Brown