The patients with bipolar disorder present with manic episodes characterized by diminished need for sleep, irritability, excessive talking, pressured speech, racing thoughts, excessive pleasurable activities and evidence of distractibility.

Major depressive episodes are characterized by depressed mood, hypersomnia or insomnia, psychomotor retardation, loss of energy, decreased ability to concentrate and even suicidal attempts.

In mixed episodes, the patient experiences both manic disorders and major depression. Depressive events last for at least 1 week. Mood disturbances are unrelated to substance abuse or medical conditions and result in marked depression and disruption of social activities.

The diagnosis of bipolar disorder is mainly clinical. The following investigations may be helpful in the diagnosis.

Laboratory investigations:

• The level of thyroid hormones should be evaluated to rule out hypothyroidism (which causes depression) and hyperthyroidism (which causes mania).
• Erythrocyte sedimentation rate should also be measured to rule out any infection.
• Drug and alcohol screening should also be done.
• Liver function tests and tests for rapid plasma reagent (RPR) are also important.

Imaging studies:

Brain imaging via CT scan (computerized tomography) or MRI (magnetic resonance imaging) should also be done to rule out infections, stroke or tumor.

Procedures:

Electroencephalography should be done if temporal lobe epilepsy is suspected.

The treatment of bipolar disorder directly depends upon severity of disease. In severe disease, the patient should be hospitalized. Less severe cases can be treated on an outpatient basis.

A number of drugs are used to reduce anxiety and depression in these patients. These including antipsychotics, valproate and benzodiazepines.

Manic episodes are usually treated with lithium, which may also have a neuro-protective role [10].

Certain lifestyle changes are also associated with a better prognosis. Patients with bipolar depressive illness are advised to have adequate levels of omega-3 in their diet [11]. Salt intake should be reduced. They should also be encouraged to plan a proper exercise schedule.

Bipolar disorder is a severely impairing illness and has a deep impact on many aspects of the life of the patient [7]. A typical patient with bipolar disorder has an average of 8 to 10 manic episodes over a lifetime. It is not yet clear how frequently childhood disorder persists into adulthood or as future illness.

Patients suffering from bipolar disorder also have an increased risk for the development of respiratory and circulatory disorders [8]. Owing to these co-morbidities, the patients suffering from bipolar disorder die an average of 9 years earlier as compared to the normal population [9].

Genetic predisposition plays a key role in the development of this disease. Major life stressors and external factors can trigger the initial and subsequent episodes.

Genetic factors

Bipolar disorder has a well-documented genetic predisposition. The concordance of this disease in monozygotic twins is around 40 to 70% whereas in dizygotic twins, it is 5 to 25%. 50% of the patients have atleast one parent with a mood disorder.

The major genes involved in the development of bipolar disorder are the ANK3, CACNA1C and CLOCK genes [1] [2].

Biochemical factors

Drugs that increase the levels of monoamine neurotransmitters (such as serotonin, norepinephrine and dopamine) can cause bipolar disorder. High glutamate level are also known to have an association. Calcium channel blockers and hormonal imbalances may also contribute to bipolar disorder.

Environmental factors

External pressure and work load may also be a cause of increased stress in these patients. Pregnancy, for example, is a particular stress for women with a manic-depressive illness history.

Bipolar disorder is one of the most common mental illnesses. The age of onset is usually 15 to 30 years. The incidence is greater in the higher socioeconomic classes.

In the United States, the prevalence of bipolar disease varies from 1 to 1.6%. Studies indicate differences in prevalence of bipolar disease to be 1.0% for bipolar I disease and 1.1% for bipolar II disease [3].

Worldwide, the prevalence rate is 0.3-1.5%. The lifetime prevalence for bipolar disorder (BP-I) is 0.6%. For bipolar II disorder (BP-II), the prevalence is 0.4% whereas for sub-threshold bipolar disorder, it is 1.4% [4].

Patients suffering from bipolar disorder also commonly suffer from other disorders such as cardiovascular disease, diabetes mellitus, obesity and mental disorders [5]. These disorders are the major source of mortality and morbidity in these patients.

The pathophysiology of bipolar disorder is not fully understood.

The role of genetic factors in predisposing the patient to this disease is well-documented. The underlying dysregulation of biogenic amines or neurotransmitters (especially serotonin, norepinephrine and dopamine) is also well known.

Magnetic resonance imaging (MRI) findings suggest abnormalities in the prefrontal cortical areas, striatum and amygdala.

Functional neuroimaging studies also reveal the presence of hyperactivity and hypoactivity in certain regions of the brain in this illness [6].

Bipolar disorder cannot be prevented; however, the mood swings can be controlled by medication.

Bipolar disorder is a group of mood disorders that are characterized by episodes of mania and depression. Bipolar disorder has two common types; bipolar I (BP-I) and bipolar II (BP-II).

Bipolar I disorder is the more severe of the two and is characterized by at least one manic or mixed episode alternating with episodes of major depression. It causes marked impairment and requires hospitalization.

In contrast, bipolar II disorder is characterized by at least one episode of major depression and at least one episode of a mild form of mania (hypomania).

Bipolar disorder is a common severe and persistent mental illness which is characterized by episodes of depression and irritability. The disease is commonly diagnosed around the age of 21 years. The severity of the disease varies from patient to patient. Medications can be used to control depression and mood swings in these patients.

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