Introduction
Bipolar disorder, also known as manic-depressive illness, is a brain disorder that causes unusual shifts in a person's mood, energy, and ability to function. Different from the normal ups and downs that everyone goes through, the symptoms of bipolar disorder are severe. They can result in damaged relationships, poor job or school performance, and even suicide. But there is good news: bipolar disorder can be treated, and people with this illness can lead full and productive lives than two million American adults, 1 or about one percent of the population age 18 and older in any given year, 2 have bipolar disorder. Bipolar disorder typically develops in late adolescence or early adulthood. However, some people have their first symptoms during childhood, and some develop them late in life. It is often not recognized as an illness, and people may suffer for years before it is properly diagnosed and treated. Like diabetes or heart disease, bipolar disorder is a long-term illness that must be carefully managed throughout a person's life. "Manic-depression distorts moods and thoughts, incites dreadful behaviors, destroys the basis of rational thought, and too often erodes the desire and will to live. It is an illness that is biological in its origins, yet one that feels psychological in the experience of it; an illness that is unique in conferring advantage and pleasure, yet one that brings in its wake almost unendurable suffering and, not infrequently, suicide. "I am fortunate that I have not died from my illness, fortunate in having received the best medical care available, and fortunate in having the friends, colleagues, and family that I do." Kay Redfield Jamison, Ph.D., An Unquiet Mind, 1995, p. 6. (Reprinted with permission from Alfred A. Knopf, a division of Random House, Inc.)

What Are the Symptoms of Bipolar Disorder?
Bipolar disorder causes dramatic mood swings—from overly "high" and/or irritable to sad and hopeless, and then back again, often with periods of normal mood in between. Severe changes in energy and behavior go along with these changes in mood. The periods of highs and lows are called episodes of mania and depression.

Signs and symptoms of mania (or a manic episode) include:

• Increased energy, activity, and restlessness
• Excessively "high," overly good, euphoric mood
• Extreme irritability
• Racing thoughts and talking very fast, jumping from one idea to another
• Distractibility, can't concentrate well
• Little sleep needed
• Unrealistic beliefs in one's abilities and powers
• Poor judgment
• Spending sprees
• A lasting period of behavior that is different from usual
• Increased sexual drive
• Abuse of drugs, particularly cocaine, alcohol, and sleeping medications
• Provocative, intrusive, or aggressive behavior
• Denial that anything is wrong

Signs and symptoms of depression (or a depressive episode) include:

• Lasting sad, anxious, or empty mood
• Feelings of hopelessness or pessimism
• Feelings of guilt, worthlessness, or helplessness
• Loss of interest or pleasure in activities once enjoyed, including sex
• Decreased energy, a feeling of fatigue or of being "slowed down"
• Difficulty concentrating, remembering, making decisions
• Restlessness or irritability
• Sleeping too much, or can't sleep
• Change in appetite and/or unintended weight loss or gain
• Chronic pain or other persistent bodily symptoms that are not caused by physical illness or injury
• Thoughts of death or suicide, or suicide attempts

A depressive episode is diagnosed if five or more of these symptoms last most of the day, nearly every day, for a period of 2 weeks or longer.

A mild to moderate level of mania is called hypomania. Hypomania may feel good to the person who experiences it and may even be associated with good functioning and enhanced productivity. Thus even when family and friends learn to recognize the mood swings as possible bipolar disorder, the person may deny that anything is wrong. Without proper treatment, however, hypomania can become severe mania in some people or can switch into depression.

Sometimes, severe episodes of mania or depression include symptoms of psychosis (or psychotic symptoms). Common psychotic symptoms are hallucinations (hearing, seeing, or otherwise sensing the presence of things not actually there) and delusions (false, strongly held beliefs not influenced by logical reasoning or explained by a person's usual cultural concepts). Psychotic symptoms in bipolar disorder tend to reflect the extreme mood state at the time. For example, delusions of grandiosity, such as believing one is the President or has special powers or wealth, may occur during mania; delusions of guilt or worthlessness, such as believing that one is ruined and penniless or has committed some terrible crime, may appear during depression. People with bipolar disorder who have these symptoms are sometimes incorrectly diagnosed as having schizophrenia, another severe mental illness.

It may be helpful to think of the various mood states in bipolar disorder as a spectrum or continuous range. At one end is severe depression, above which is moderate depression and then mild low mood, which many people call "the blues" when it is short-lived but is termed "dysthymia" when it is chronic. Then there is normal or balanced mood, above which comes hypomania (mild to moderate mania), and then severe mania.

In some people, however, symptoms of mania and depression may occur together in what is called a mixed bipolar state. Symptoms of a mixed state often include agitation, trouble sleeping, and significant change in appetite, psychosis, and suicidal thinking. A person may have a very sad, hopeless mood while at the same time feeling extremely energized.

Diagnosis of Bipolar Disorder
Like other mental illnesses, bipolar disorder cannot yet be identified physiologically—for example, through a blood test or a brain scan. Therefore, a diagnosis of bipolar disorder is made on the basis of symptoms, course of illness, and, when available, family history. The diagnostic criteria for bipolar disorder are described in the Diagnostic and Statistical Manual for Mental Disorders, fourth edition (DSM-IV).3 Descriptions offered by people with bipolar disorder give valuable insights into the various mood states associated with the illness:

Depression: I doubt completely my ability to do anything well. It seems as though my mind has slowed down and burned out to the point of being virtually useless…. [I am] haunt[ed]… with the total, the desperate hopelessness of it all…. Others say, "It's only temporary, it will pass, you will get over it," but of course they haven't any idea of how I feel, although they are certain they do. If I can't feel, move, think or care, then what on earth is the point?

Hypomania: At first when I'm high, it's tremendous… ideas are fast… like shooting stars you follow until brighter ones appear…. All shyness disappears, the right words and gestures are suddenly there… uninteresting people, things become intensely interesting. Sensuality is pervasive, the desire to seduce and be seduced is irresistible. Your marrow is infused with unbelievable feelings of ease, power, well-being, omnipotence, euphoria… you can do anything… but, somewhere this changes.

Mania: The fast ideas become too fast and there are far too many… overwhelming confusion replaces clarity… you stop keeping up with it—memory goes. Infectious humor ceases to amuse. Your friends become frightened…. everything is now against the grain… you are irritable, angry, frightened, uncontrollable, and trapped.

Signs and symptoms that may accompany suicidal feelings include:

• Talking about feeling suicidal or wanting to die
• Feeling hopeless, that nothing will ever change or get better
• Feeling helpless, that nothing one does makes any difference
• Feeling like a burden to family and friends
• Abusing alcohol or drugs
• Putting affairs in order (e.g., organizing finances or giving away possessions to prepare for one's death)
• Writing a suicide note
• Putting oneself in harm's way, or in situations where there is a danger of being killed

If you are feeling suicidal or know someone who is:

• Call a doctor, emergency room, or 911 right away to get immediate help
• Make sure you, or the suicidal person, are not left alone
• Make sure that access is prevented to medication, weapons, or other items that could be used for self-harm

While some suicide attempts are carefully planned over time, others are impulsive acts that have not been well thought out; thus, the final point in the box above may be a valuable long-term strategy for people with bipolar disorder. Either way, it is important to understand that suicidal feelings and actions are symptoms of an illness that can be treated. With proper treatment, suicidal feelings can be overcome.

What Is the Course of Bipolar Disorder?
Episodes of mania and depression typically recur across the life span. Between episodes, most people with bipolar disorder are free of symptoms, but as many as one-third of people have some residual symptoms. A small percentage of people experience chronic unremitting symptoms despite treatment.4 The classic form of the illness, which involves recurrent episodes of mania and depression, is called bipolar I disorder. Some people, however, never develop severe mania but instead experience milder episodes of hypomania that alternate with depression; this form of the illness is called bipolar II disorder. When four or more episodes of illness occur within a 12-month period, a person is said to have rapid-cycling bipolar disorder. Some people experience multiple episodes within a single week, or even within a single day. Rapid cycling tends to develop later in the course of illness and is more common among women than among men.

Can Children and Adolescents Have Bipolar Disorder?
Both children and adolescents can develop bipolar disorder. It is more likely to affect the children of parents who have the illness.

Unlike many adults with bipolar disorder, whose episodes tend to be more clearly defined, children and young adolescents with the illness often experience very fast mood swings between depression and mania many times within a day.6 Children with mania are more likely to be irritable and prone to destructive tantrums than to be overly happy and elated. Mixed symptoms also are common in youths with bipolar disorder. Older adolescents who develop the illness may have more classic, adult-type episodes and symptoms.

Bipolar disorder in children and adolescents can be hard to tell apart from other problems that may occur in these age groups. For example, while irritability and aggressiveness can indicate bipolar disorder, they also can be symptoms of attention deficit hyperactivity disorder, conduct disorder, oppositional defiant disorder, or other types of mental disorders more common among adults such as major depression or schizophrenia. Drug abuse also may lead to such symptoms.

For any illness, however, effective treatment depends on appropriate diagnosis. Children or adolescents with emotional and behavioral symptoms should be carefully evaluated by a mental health professional. Any child or adolescent who has suicidal feelings, talks about suicide, or attempts suicide should be taken seriously and should receive immediate help from a mental health specialist.

What Causes Bipolar Disorder?
Scientists are learning about the possible causes of bipolar disorder through several kinds of studies. Most scientists now agree that there is no single cause for bipolar disorder—rather, many factors act together to produce the illness.

Because bipolar disorder tends to run in families, researchers have been searching for specific genes—the microscopic "building blocks" of DNA inside all cells that influence how the body and mind work and grow—passed down through generations that may increase a person's chance of developing the illness. But genes are not the whole story. Studies of identical twins, who share all the same genes, indicate that both genes and other factors play a role in bipolar disorder. If bipolar disorder were caused entirely by genes, then the identical twin of someone with the illness would always develop the illness, and research has shown that this is not the case. But if one twin has bipolar disorder, the other twin is more likely to develop the illness than is another sibling.7

In addition, findings from gene research suggest that bipolar disorder, like other mental illnesses, does not occur because of a single gene.8 It appears likely that many different genes act together, and in combination with other factors of the person or the person's environment, to cause bipolar disorder. Finding these genes, each of which contributes only a small amount toward the vulnerability to bipolar disorder, has been extremely difficult. But scientists expect that the advanced research tools now being used will lead to these discoveries and to new and better treatments for bipolar disorder.