About one in every 160 people (0.6%) develop bipolar disorder at some point in their life. It affects men and women at equal rates, and it’s found among all ages, races, ethnic groups, and social classes.

There is no simple answer to what causes bipolar disorder. Several factors play a part in the onset, including:

  • A genetic or family history of bipolar disorder
  • Environmental stressors and stressful life events
  • Biological factors

Research shows that the risk for bipolar disorder results from the influence of genes acting together with environmental and biological factors.

Genetic Factors

Research shows that the risk for bipolar disorder results from the influence of genes acting together with environmental factors. A family history of bipolar disorder does not necessarily mean children or other relatives will develop the disorder. However, studies have shown that bipolar disorder does run in families, and a family history of bipolar disorder is one of the strongest and most consistent risk factors for the disorder.

People with a parent or sibling who has it are four to six times more likely to develop the illness compared to individuals who do not have a family history of bipolar disorder. The risk is highest for an identical twin of a person with bipolar disorder. The identical twin has a 40 to 70 percent chance of developing the disorder.

Environmental Factors and Life Events 

Others believe the environment plays a key role in whether someone will develop bipolar disorder. For example, sleep deprivation, substance abuse, and stressful life events, such as family conflict or loss of a job or a loved one can increase the likelihood of developing the disorder.

Biological Factors

An imbalance of the neurotransmitters norepinephrine and serotonin is also linked to bipolar disorder. Neurotransmitters are brain chemicals that communicate information throughout the brain and body. The exact role of these neurotransmitters in bipolar disorder is not yet understood.

Here are some additional articles you might find helpful:

What Causes Bipolar Disorder

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