Introduction:

Bipolar disorder, or manic-depressive illness, is characterized by moods that swing between two opposite poles:

• Periods of mania with exaggerated euphoria, irritability, or both
• Episodes of depression

Although chemical imbalances in the brain are a key component of bipolar disorder, it is a complex condition that involves genetic, environmental, and other factors.

Bipolar Disorder Categories

Bipolar disorder is classified according to the pattern and severity of the symptoms as bipolar disorder I, bipolar disorder II, or cyclothymic disorder. Patients with one type may develop another. Nevertheless, they are distinct enough to merit separate classifications, and some experts believe these conditions are actually separate disorders with different biologic factors that account for their differences.

Bipolar Disorder I. Bipolar disorder I is characterized by at least one manic episode, with or without major depression, that lasts for at least 7 days. In 60 - 70% of cases, manic episodes precede or follow depressive episodes in a regular pattern. Episodes are more acute and severe than in the other two categories.

Without treatment, patients average four episodes of dysregulated mood each year. With mania, either euphoria or irritability may mark the phase. In addition, there are significant negative effects (such as sexual recklessness, excessive and impulsive shopping, and sudden traveling) on a patient's social life, performance at work, or both. Untreated mania lasts at least a week, and it can last for months. Typically, depressive episodes tend to last 6 - 12 months, if left untreated.

Bipolar Disorder II and Hypomania. Bipolar disorder II is characterized by episodes of predominantly depressive symptoms, with occasional episodes of hypomania, which last for at least 4 days. Hypomania is similar to mania, but the symptoms (typically euphoria) are less severe and do not last as long.

Patients do not experience manic or mixed episodes, and most return to fully functional levels between episodes. However, bipolar II patients have a more chronic course, significantly more depressive episodes, and shorter periods of being well between episodes than patients with type I have. It is highly associated with the risk for suicide.

Cyclothymic Disorder. While cyclothymic disorder is not as severe as either bipolar disorder II or I, the condition is more chronic. Hypomanic symptoms tend toward irritability as compared to the more euphoric symptoms of bipolar II. (One report, in fact, referred to these patients as having "darker" natures, while bipolar II patients were "sunnier.")

The disorder lasts at least 2 years, with single episodes persisting for more than 2 months. Cyclothymic disorder may be a precursor to full-blown bipolar disorder in some people or it may continue as a low-grade chronic condition.

Symptoms of Bipolar Disorder

Symptoms of the Depression Phase. The symptoms of depression experienced in bipolar disorder are almost identical to those of major depression, the primary form of unipolar depressive disorder. They include:

• Sad mood
• Fatigue or loss of energy
• Sleep problems such as insomnia, excessive sleeping, or shallow sleep with frequent awakenings
• Appetite changes
• Diminished ability to concentrate or to make decisions
• Agitation or markedly sedentary behavior
• Feelings of guilt, pessimism, helplessness, or low self-esteem
• Loss of interest or pleasure in life
• Thoughts of, or attempts at, suicide

Distinguishing Between Unipolar and Bipolar Depression. It is often difficult to differentiate between unipolar and bipolar depression, particularly in patients with bipolar II disorder. They may differ in the following ways:

• Bipolar depression typically lasts 2 - 3 months -- not as long as in major depression (although left untreated some bipolar disorder episodes can last 6 - 12 months or longer).
• People with unipolar depression can still experience a variety of other moods, but none meet the criteria for a manic state.
• Depressive symptoms in those with bipolar disorder tend to vary. For example, some patients experience increased sleep, gain weight, and feel a heaviness and slowness in their bodies. Other patients with bipolar depression experience impaired sleep, but unlike patients with unipolar depression, they do not feel sleepy the next day.
• Bipolar depressive episodes tend to develop more gradually than do those caused by major depression.

Symptoms of the Acute Manic Phase. The acute pure manic phase is always characterized by mood elevation, presented in the following ways:

• Exaggerated euphoria (a feeling of great happiness or well-being)
• Irritability
• Both euphoria and irritability

The episode lasts for at least few days but, in some cases, the episode may last weeks or even months and may be severe enough to require hospitalization.

Other symptoms must also be present to make a diagnosis. Some mental health professionals use the mnemonic device DIGFAST to identify them. In general, for a diagnosis of mania, a patient must have experienced either euphoria with three DIGFAST symptoms or irritability with four of these symptoms:

• D. Distractibility. This is the most common symptom, and it is usually characterized by the inability to pay attention to any activity for very long.
• I. Insomnia in mania typically means having high energy and requiring less sleep. (This differs from insomnia in depression, in which the patient has low energy plus an inability to sleep.)
• G. Grandiosity. Patients with this symptom have an inflated sense of themselves, which, in severe cases, can be delusional. Close to 60% of all manic patients experience feelings of being all-powerful. Sometimes they feel that they are godlike or have celebrity status.
• F. Flight of ideas. Thoughts literally race.
• A. Activity. The patient may show an increase in intensity in goal-directed activities, which are related to social behavior, sexual activity, work or school.
• S. Speech. The patient may talk excessively.
• T. Thoughtlessness. Excessive involvement in high-risk activities is present (such as unrestrained shopping, promiscuity). Mood disturbance may be severe enough to damage one's job or social functioning or one's relationships with others. Some patients require hospitalization to prevent harm to others or to themselves.

Some patients with bipolar I may experience psychotic symptoms, including thought disorders, hallucinations, and catatonia (a state in which the patient goes into a stupor for long periods, which may give way to short periods of extreme excitement).

Hypomania. With hypomania the symptoms of mania are milder and of shorter duration (but they last at least 4 days). They do not affect social or work life as dramatically.

Mixed Mania State Symptoms. Mixed mania (also called mixed episodes or dysphoric mania) are manic episodes that also have a depressive component. In such a state, mania is present to a significant degree, but depression is present most of the day and nearly every day. Such mixed symptoms occur for at least a week.

Depressive Mixed State Symptoms. Depressive mixed state is characterized by major depression as the primary emotional state with manic features (such as irritability, distractibility, and racing thoughts). Such patients may receive an inaccurate diagnosis of unipolar depression.