The exact cause of bipolar disorder is unknown. Scientists believe there are probably a number of causes for this illness. It is believed that imbalances in certain brain chemicals or abnormalities in message transfer along neuronal pathways are involved.
Familial patterns for this disorder have genetic researchers trying to identify specific genes which might be involved in its being passed down in families. Studies of identical twins, have shown that though there is a higher prevalence of a second identical twin having the disorder when one twin is diagnosed with it, it is not always present therefore ruling out genetics as the only causative factor.
Substance related issues, perinatal development, head trauma, environmental factors and a number of stressors are all some possible factors that when combined with a number of genetic factors may work together to cause the disorder.
Improvements in brain-imaging technology allow scientific researchers to take pictures of the brain in people with bipolar disorder and other mental illnesses. This examination of specific brain structures and how they function in patients with and without the disorder may lead to improved understanding of the causes of this and other mental disorders and improve the ability to predict which treatments will be most effective for specific for patients.