We all experience a variety of moods such as happiness, sadness, and anger. Unpleasant moods and changes in mood are normal reactions in everyday life, and we can often identify the events that caused our mood to change. However, when we experience extreme mood changes that affect how we behave and function, these changes are often the result of a mood disorder.
Bipolar disorder (formerly known as manic-depressive disorder) is a mood disorder that consists of periods of extremely elevated mood (mania), extremely low mood (depression), and normal mood.
Bipolar disorder typically begins for people during adolescence and early adulthood. It is unusual for bipolar disorder to begin in childhood without strong familial risk factors, and it is rare for its onset to occur after the age of 60 (unless it is associated with another medical condition). Bipolar disorder occurs in about 2% of the adult population, and men and women are affected equally.
There is no single, proven cause of bipolar disorder, but research suggests that it is the result of abnormalities in the way some nerve cells in the brain function or communicate. Researchers also believe that there is a definite genetic link (family history) in which there is a higher risk for people who have a parent or full sibling (i.e., a first-degree relative) with bipolar disorder.
Whatever the precise nature of the cause of bipolar disorder, it clearly makes people with the disorder more vulnerable to emotional and physical stresses. As a result, upsetting life experiences, alcohol, illicit drug use, lack of sleep, or other stresses can trigger episodes of illness, even though these stresses do not actually cause the disorder.
Bipolar disorder is not the fault of the person suffering from it and is not the result of a "weak" or unstable personality. Rather, bipolar disorder is a treatable medical condition.
Bipolar disorder is a condition in which the person's mood changes in cycles - from extremely high or irritable to extremely low and hopeless - over weeks to months. The nature of these mood changes varies from one person to the next. A person may go through periods of elevated mood, depressed mood, and times when mood is normal. The period of time that the extreme high and low moods are experienced are called episodes of mania and depression.
Mania: During a manic episode, people experience a high, irritable, angry, or aggressive mood for at least one week. In addition, they will experience 3 or more of the following:
A manic episode may also include psychotic symptoms such as delusions (firmly believing things that are not true) or hallucinations (hearing, feeling, or seeing things that are not there).
Hypomania is a milder form of mania that has similar but less severe symptoms and has less negative impact on a person's daily activities. During a hypomanic episode, the person may have an elevated mood and be more productive. Because these episodes often feel good, the quest for hypomania may even cause some people with bipolar disorder to stop taking their medications. However, a hypomanic episode does not usually last for long and gradually shifts into either mania or depression. Therefore, it is important for hypomania to be treated.
Depression: During a depressive episode, the person experiences feelings of sadness or loses interest in the things they normally enjoy. At least 5 of the following additional symptoms persist for at least 2 weeks:
A depressive episode may also include symptoms such as severe anxiety, excessive worry, and other physical symptoms (e.g., pain) as well as psychotic symptoms such as delusions (firmly believing things that are not true) or hallucinations (hearing, feeling, or seeing things that are not there).
Some people with bipolar disorder experience mixed episodes that involve symptoms of both mania and depression together or alternating frequently during the day. Individuals are excitable or agitated as in mania, but they also feel irritable and depressed. Mixed episodes present the highest risk of suicide. Approximately 25% to 50% of all people with bipolar disorder have a lifetime risk of attempting suicide.
Some people with bipolar disorder also experience problems with movement, called catatonic symptoms. These symptoms include physical agitation, immobility, and unusual movements or body positions.
Patterns of bipolar disorder
People with bipolar disorder vary in the types and frequency of episodes that they experience. Some people may have equal numbers of manic and depressive episodes, while others may have mostly one type (usually depression).
While several years can pass between the first few episodes without treatment, most people eventually have more frequent episodes. Episodes can last for days, weeks, months, or sometimes even years. For some people, the episodes have rapid cycling where they experience at least 4 episodes per year in any combination of mania, hypomania, mixed, or depression.
According to the episode patterns, bipolar disorder can be classified as: