Scientists are learning
about the possible causes of bipolar disorder through several kinds of
studies. Most scientists now agree that there is no single cause for
bipolar disorder - rather, many factors act together to produce the
illness.
Because bipolar disorder tends to run in families,
researchers have been searching for specific genes - the microscopic
"building blocks" of DNA inside all cells that influence how the body and
mind work and grow - passed down through generations that may increase a
person's chance of developing the illness.
But genes are not the
whole story. Studies of identical twins, who share all the same genes,
indicate that both genes and other factors play a role in bipolar
disorder. If bipolar disorder were caused entirely by genes, then the
identical twin of someone with the illness would always develop the
illness, and research has shown that this is not the case. But if one twin
has bipolar disorder, the other twin is more likely to develop the illness
than is another sibling.
In addition, findings from gene research
suggest that bipolar disorder, like other mental illnesses, does not occur
because of a single gene. It appears likely that many different genes act
together, and in combination with other factors of the person or the
person's environment, to cause bipolar disorder. Finding these genes, each
of which contributes only a small amount toward the vulnerability to
bipolar disorder, has been extremely difficult. But scientists expect that
the advanced research tools now being used will lead to these discoveries
and to new and better treatments for bipolar
disorder.
Brain-imaging studies are helping scientists learn what
goes wrong in the brain to produce bipolar disorder and other mental
illnesses. New brain-imaging techniques allow researchers to take pictures
of the living brain at work, to examine its structure and activity,
without the need for surgery or other invasive procedures. These
techniques include magnetic resonance imaging (MRI), positron emission
tomography (PET), and functional magnetic resonance imaging (fMRI). There
is evidence from imaging studies that the brains of people with bipolar
disorder may differ from the brains of healthy individuals. As the
differences are more clearly identified and defined through research,
scientists will gain a better understanding of the underlying causes of
the illness, and eventually may be able to predict which types of
treatment will work most effectively.
Related
Topics:
What is Bipolar
Disorder?
Symptoms of Bipolar
Disorder
Treatment of Bipolar
Disorder
Bipolar Disorder in Children
and Adolescents
Source: U.S. National
Institute of Mental Health |
