Biological Causes of Bipolar Disorder

Bipolar disorder is a serious mood disorder in which a person’s mood goes from one extreme to another. This disorder affects thousands of people each year making it one of the most common disorders in the country.

Similar to that of addiction, bipolar disorder is thought to be caused partially by both environmental factors and biological causes. While more research still needs to be done, researchers have identified several reasons for how bipolar disorder can be caused by biological factors.

Some disorders such as bipolar disorder can be caused by a person’s genetic code, including some of the following examples:

  • Neurotransmitters – There are three chemicals in the brain that help with a person’s emotional function: norepinephrine, serotonin and dopamine. Both norepinephrine and serotonin are responsible in determining a person’s mood, while dopamine provides a person with feelings of satisfaction and pleasure. When these chemicals are unbalanced, they can impact a person’s psychological functioning, eventually leading to symptoms of bipolar disorder.
  • Cortisol – Cortisol is another chemical in the brain that is directly linked to a person’s stress response. When a person is under consistent stress, this chemical is secreted, and it can cause damage to brain function (as his or her brain is not getting the opportunity to recover from the outburst of stress) leading to mood disorders such as bipolar disorder.

The most significant biological causes for bipolar disorder comes from genetics. Many studies show how parents’ genes impact their children:

  • Roughly 50% of people with dipolar disorder have another family member with a mood disorder. (
  • A child with a parent who has bipolar disorder has a 5 to 25 percent chance of inheriting it. (
  • If one identical twin has bipolar disorder, the chances of the other twin developing it increases eightfold compared to fraternal twins. (
  • Bipolar II is the most common affective disorder in families that have both bipolar I and bipolar II. (Johns Hopkins University)
  • 51% of children from bipolar parents experience a disorder such as depression or ADHD. (Stanford University)

While many environmental causes can lead to the development of bipolar disorder, the statistics surrounding the biological causes are also very significant. By developing an awareness of the potential to pass a disorder to a child, a parent can be prepared to look for symptoms of bipolar disorder to protect their children from the consequences of an untreated diagnosis.