As of 2015, experts do not know the root cause for bipolar disorder, but they have linked several factors to development of the condition, according to Mayo Clinic. Heredity, physiological brain differences and an imbalance of neurotransmitters have been linked to bipolar disorder.
Bipolar patients have a different brain structure than people without the condition, Mayo Clinic states. Researchers believe that understanding these differences can help diagnose people with the condition in the future.
An imbalance in brain chemicals, known as neurotransmitters, is linked to mood disorders including bipolar disorder, Mayo Clinic says. These chemicals occur naturally in the brain.
People with a close relative, such as a parent or sibling, with bipolar disorder are at a higher risk for developing the condition, Mayo Clinic reports. Researchers are currently looking for genes that may be involved in family members passing along the condition.
In addition to heredity, additional risk factors for bipolar disorder include enduring a traumatic experience and periods of high stress, Mayo Clinic says. Drug and alcohol use can contribute to development of the disorder as well.
People with bipolar disorder often have associated health conditions, Mayo Clinic reports. They include attention-deficit/hyperactivity disorder, post-traumatic stress disorder, anxiety disorders and substance abuse. They are also more likely to suffer from thyroid and heart disease as well as obesity.