What Is the Biochemical Makeup of Bipolar Disorder?

Statistics from the U.S. National Library show as many as 5.7 million American adults are diagnosed with bipolar disorder in any given year. Bipolar disorder is a severe mood disorder that can have a debilitating effect on a person's everyday life. As with most psychological disorders, chemical imbalances in the brain play a significant role in the symptoms experienced by those who suffer from this condition.

Identification

• Bipolar disorder, also known as manic depressive disorder, is classified as a mood disorder. Episodes of mania where individuals experience euphoria, overactivity, and loss of inhibitions are followed by periods of depression. It can be a debilitating condition depending on its severity, because individuals undergo extreme personality changes during manic episodes. This condition arises as result of biochemical imbalances present in the brain that affect how the nerve cells communicate with each other.

Causes

• Bipolar disorder shows a higher than normal occurrence within generational family lines. Multiple genes have been linked to the disorder, and as a result, biochemical imbalances are prevalent within the brain's chemistry. Certain signal-sending cells within the brain are shown to be 30 percent higher in number for those with bipolar disorder. This higher concentration of cells and signals accounts for hypersensitivity toward emotional and physical stressors.

Neurotransmitters

• Chemicals in the brain called neurotransmitters are responsible for every function within the human body. These chemical transmissions coordinate all bodily processes, movements, thoughts, and emotions. Three neurotransmitters in particular (dopamine, serotonin, and norepinephrine) play a significant role in bipolar disorder. These chemicals are responsible for stress responses, mood regulation, and cognitive functions, as well as the pleasure and reward centers of the brain. Unless these chemicals are present in the right amounts, any number of psychological or mood disturbances can take place.

Clinical Research

• An article in the October 2000 American Journal of Psychiatry, "Evidence of Brain Abnormalities in Bipolar Disorder," reports on a study done by a team of researchers at the University of Michigan in Ann Arbor. Jon-Kar Zubieta, M.D., led the team in performing a special brain imaging technique that tracked the brain activity of bipolar patients. The results of the study showed a higher density of neuronal cells emitting dopamine, serotonin, and norepinephrine. These cells appeared in concentrated areas throughout the brain, and remained active, even when the patients were at rest.

Medication Treatment

• The overall goal of prescription medication in treating bipolar disorder is to stabilize, or regulate, neurotransmitter levels within the brain. Mood stabilizers are the types of drugs most commonly used to treat this condition. Lithium is a standard medication treatment; however, it does pose a risk of blood poisoning if the prescription amount is too much. Other medications include Seroquel, Depakote, and Tegretol. Because each person's brain chemistry is different, finding the right medication and dosage may entail a trial and error process.