context: Bipolar I disorder (pronounced "bipolar one" and also known as manic-depressive disorder or manic depression) is a form of mental illness. A person affected by bipolar I disorder has had at least one manic episode in his or her life. A manic episode is a period of abnormally elevated mood and high energy, accompanied by abnormal behavior that disrupts life. Most people with bipolar I disorder also suffer from episodes of depression. Often, there is a pattern of cycling between mania and depression. This is where the term "manic depression" comes from. In between episodes of mania and depression, many people with bipolar I disorder can live normal lives. Understanding Bipolar Disorder Virtually anyone can develop bipolar I disorder. About 2.5% of the U. S. population suffers from bipolar disorder -- almost 6 million people. Most people are in their teens or early 20s when symptoms of bipolar disorder first appear. Nearly everyone with bipolar I disorder develops it before age 50. People with an immediate family member who has bipolar are at higher risk. During a manic episode in someone with bipolar disorder, elevated mood can manifest itself as either euphoria (feeling "high") or as irritability. Abnormal behavior during manic episodes includes: Flying suddenly from one idea to the next Rapid, "pressured" (uninterruptable), and loud speech Increased energy, with hyperactivity and a decreased need for sleep Inflated self-image Excessive spending Hypersexuality Substance abuse People in manic episodes may spend money far beyond their means, have sex with people they wouldn't otherwise, or pursue grandiose, unrealistic plans. In severe manic episodes, a person loses touch with reality. They may become delusional and behave bizarrely. Untreated, an episode of mania can last anywhere from a few days to several months. Most commonly, symptoms continue for a few weeks to a few months. Depression may follow shortly after, or not appear for weeks or months. Many people with bipolar I disorder experience long periods without symptoms in between episodes. A minority has rapid-cycling symptoms of mania and depression, in which they may have distinct periods of mania or depression four or more times within a year. People can also have mood episodes with "mixed features," in which manic and depressive symptoms occur simultaneously, or may alternate from one pole to the other within the same day. Depressive episodes in bipolar disorder are similar to "regular" clinical depression, with depressed mood, loss of pleasure, low energy and activity, feelings of guilt or worthlessness, and thoughts of suicide. Depressive symptoms of bipolar disorder can last weeks or months, but rarely longer than one year. Manic episodes in bipolar I disorder require treatment with drugs, such as mood stabilizers and antipsychotics, and sometimes sedative-hypnotics which include benzodiazepines such as clonazepam ( Klonopin) or lorazepam ( Ativan). Mood Stabilizers Lithium: This simple metal in pill form is especially effective at controlling mania that involves classical euphoria rather than mixtures of mania and depression simultaneously. Lithium has been used for more than 60 years to treat bipolar disorder. Lithium can take weeks to work fully, making it better for maintenance treatment than for sudden manic episodes. Blood levels of lithium as well as tests to measure kidney and thyroid functioning must be monitored to avoid side effects. Valproate ( Depakote): This antiseizure medication also works to level out moods. It is faster acting than lithium for an acute episode of mania. It is also often used "off label" for prevention of new episodes. As a mood stabilizer that can be used by a "loading dose" method -- beginning at a very high dose -- valproate allows the possibility of significant improvement in mood as early as four to five days. Some other antiseizure drugs, notably carbamazepine ( Tegretol) and lamotrigine ( Lamictal), can have value in treating or preventing manias or depressions. Other antiseizure medicines that are less well-established but still sometimes used experimentally for the treatment of bipolar disorder, such as oxcarbazapine ( Trileptal). Antipsychotics For severe manic episodes, traditional antipsychotics (such as Haldol, Loxapine, or Thorazine) as well as newer antipsychotic drugs -- also called atypical antipsychotics -- may be necessary. Cariprazine ( Vraylar) is a newly approved antipsychotic to treat manic or mixed episodes. Aripiprazole ( Abilify), asenapine ( Saphris), clozapine ( Clozaril), olanzapine ( Zyprexa), quetiapine ( Seroquel), risperidone ( Risperdal), and ziprasidone ( Geodon) are often used, and many other drugs are available. The antipsychotic lurasidone ( Latuda)is approved for use -- either alone or with lithium or valproate ( Depakote) -- in cases of bipolar I depression. Antipsychotic medicines are also sometimes used for preventive treatment. Benzodiazepines This class of drugs includes alprazolam ( Xanax), diazepam ( Valium), and lorazepam ( Ativan) and is commonly referred to as minor tranquilizers. They are sometimes used for short-term control of acute symptoms associated with mania such as agitation or insomnia, but they do not treat core mood symptoms such as euphoria or depression. Antidepressants Common antidepressants such as fluoxetine ( Prozac), paroxetine ( Paxil), and sertraline ( Zoloft) have not been shown to be as effective for treating depression in bipolar I disorder as in unipolar depression. In a small percentage of people, they can also set off or worsen a manic episode in a person with bipolar disorder. However, studies have shown that for bipolar II depression, some antidepressants (such as Prozac and Zoloft) may be safe and more helpful than in bipolar I depression. For these reasons, the first-line treatments for depression in bipolar disorder involve medicines that have been shown to have antidepressant properties but also no known risk for causing or worsening mania. The three FDA-approved treatments for bipolar depression are lurasidone ( Latuda), olanzapine-fluoxetine ( Symbyax) combination, quetiapine ( Seroquel) or quetiapine fumarate ( Seroquel XR). Other mood-stabilizing treatments that are sometimes recommended for treating acute bipolar depression include lithium, Depakote, and Lamictal (although none of these latter three medicines is FDA-approved specifically for bipolar depression). If these fail, after a few weeks a traditional antidepressant or other medicine may sometimes be added. Psychotherapy, such as cognitive-behavioral therapy, may also help. People with bipolar I disorder (mania or depression) have a high risk for recurrences and usually are advised to take medicines on a continuous basis for prevention. Electroconvulsive Therapy ( ECT) Despite its scary reputation, electroconvulsive therapy ( ECT) is a safe and effective treatment for both manic and depressive symptoms. ECT is often used to treat severe forms of depression or mania in bipolar I disorder when medicines may not be effective or likely to work fast enough to bring symptom relief. The causes of bipolar disorder are not well understood. It's not known if bipolar I disorder can be prevented entirely. It is possible to lower the risk of episodes of mania or depression once bipolar disorder has developed. Regular therapy sessions with a psychologist or social worker can help people to identify factors that can destabilize mood (such as poor medication adherence, sleep deprivation, drug or alcohol abuse, and poor stress management), leading to fewer hospitalizations and feeling better overall. Taking medicine on a regular basis can help to prevent future manic or depressive episodes. People with bipolar I disorder experience full episodes of mania -- the often severe abnormally elevated mood and behavior described above. These manic symptoms can lead to serious disruptions in life (for example, spending the family fortune, or having an unintended pregnancy). In bipolar II disorder, the symptoms of elevated mood never reach full-blown mania. They often pass for extreme cheerfulness, even making someone a lot of fun to be around -- the "life of the party." Not so bad, you might think -- except bipolar II disorder usually involves extensive and disabling periods of significant depression, which can often be harder to treat than if episodes of hypomania had never occurred.