Bipolar disorder, formerly known as manic-depressive illness, is a brain and behavior disorder characterized by severe shifts in a person's mood and energy, making it difficult for the person to function. More than 5.7 million American adults or 2.6 percent of the population age 18 or older in any given year have bipolar disorder. The condition typically starts in late adolescence or early adulthood, although it can show up in children and in older adults. People often live with the disorder without having it properly diagnosed and treated.

Bipolar disorder causes repeated mood swings, or episodes, that can make someone feel very high (mania) or very low (depressive). The cyclic episodes are punctuated by normal moods.

Mania Episode Signs and Symptoms:

• Increased energy, activity, restlessness
• Euphoric mood
• Extreme irritability
• Poor concentration
• Racing thoughts, fast talking, jumping between ideas
• Sleeplessness
• Heightened sense of self-importance
• Spending sprees
• Increased sexual behavior
• Abuse of drugs, such as cocaine, alcohol and sleeping medications
• Provocative, intrusive or aggressive behavior
• Denial that anything is wrong

Depressive Episode Signs:

• Sad, anxious or empty-feeling mood
• Feelings of hopelessness and pessimism
• Feelings of guilt, worthlessness and helplessness
• Loss of interest or pleasure in activities once enjoyed, including sex
• Decreased energy, fatigue
• Difficulty concentrating, remembering or making decisions
• Restlessness and irritability
• Sleeplessness or sleeping too much
• Change in appetite, unintended weight loss or gain
• Bodily symptoms not caused by physical illness or injury
• Thoughts of death or suicide

Bipolar disorder cannot yet be diagnosed physiologically by blood tests or brain scans. Currently, diagnosis is based on symptoms, course of illness, and family history. Clinicians rule out other medical conditions, such as a brain tumor, stroke or other neuropsychiatric illnesses that may also cause mood disturbance. The different types of bipolar disorder are diagnosed based on the pattern and severity of manic and depressive episodes.  Doctors usually diagnose brain and behavior disorders using guidelines from the Diagnostic and Statistical Manual of Mental Disorders, or DSM. According to the DSM, there are four basic types of bipolar disorder:

• Bipolar I Disorder is mainly defined by manic or mixed episodes that last at least seven days, or by manic symptoms that are so severe that the person needs immediate hospital care. Usually, the person also has depressive episodes, typically lasting at least two weeks. The symptoms of mania or depression must be a major change from the person’s normal behavior.
• Bipolar II Disorder is defined by a pattern of depressive episodes shifting back and forth with hypomanic episodes, but no full-blown manic or mixed episodes.
• Bipolar Disorder Not Otherwise Specified (BP-NOS) is diagnosed when a person has symptoms of the illness that do not meet diagnostic criteria for either bipolar I or II. The symptoms may not last long enough, or the person may have too few symptoms, to be diagnosed with bipolar I or II. However, the symptoms are clearly out of the person's normal range of behavior.
• Cyclothymic Disorder, or Cyclothymia, is a mild form of bipolar disorder. People who have cyclothymia have episodes of hypomania that shift back and forth with mild depression for at least two years. However, the symptoms do not meet the diagnostic requirements for any other type of bipolar disorder.
• Some people may be diagnosed with rapid-cycling bipolar disorder. This is when a person has four or more episodes of major depression, mania, hypomania, or mixed symptoms within a year.

While no cure exists for bipolar disorder, it is treatable and manageable with psychotherapy and medications. Mood stabilizing medications are usually the first choice in medication.  Lithium is the most commonly prescribed mood stabilizer. Anticonvulsant medications are usually used to treat seizure disorders, and sometimes offer similar mood-stabilizing effects as antipsychotics and antidepressants. Bipolar disorder is much better controlled when treatment is continuous. Mood changes can occur even when someone is being treated and should be reported immediately to a physician; full-blown episodes may be averted by adjusting the treatment.

In addition to medication, psychotherapy provides support, guidance and education to people with bipolar disorder and their families. Psychotherapeutic interventions increase mood stability, decrease hospitalizations and improve overall functioning. Common techniques include cognitive behavioral therapy, psychoeducation, and family therapy.

The main difference between bipolar disorder and major clinical depression is the presence of manic episodes. This is why depression alone is not enough to diagnose an individual with bipolar. However, one manic episode (meeting DMS-IV criteria) is sufficient to make a bipolar diagnosis.