Biological Cause of Bipolar Disorder

Bipolar disorder, also known as manic depression, disrupts the lives of the millions of adults diagnosed with the mental illness. The exact cause continues to elude researchers. They do know, however, that biological causes come into play.

Statistics

• According to the National Institute of Mental Health (NIMH), bipolar disorder affects nearly 5.7 million adults in the United States.

Biological Clock

• Abnormal expression to the gene that regulates our circadian rhythms (the biological clock) may contribute to bipolar disorder. Circadian rhythms follow a rough 24-hour schedule, regulating bodily functions such as hormones, sleep-wake cycles and blood pressure.

Genetics

• Family history plays a role in the development of bipolar disorder. If you have sister, brother or parent with bipolar disorder, you are up to six times more likely to develop the disorder, the NIMH reports.

Hormones

• Scientists remain unsure of the exact cause of bipolar disorder, but a neurotransmitter imbalance may be involved. Over-secretion of the stress hormone cortisol also has been linked.

Combination

• There's no single cause for bipolar disorder. It seems to be a complicated mixture of biological and environmental factors.