Is Bipolar Hereditary? Possible Genetic & Biological Links

Reviewed by Heather Cashell, LCSW

Published 12/24/2020

Bipolar disorder is one of the most common mental health disorders and affects millions of people worldwide, but did you know that having a family member with the disorder may increase the risk of it? This article will discuss the possible connection between genetics and bipolar disorder and other implications that it may have.

Does Bipolar Disorder Run In Families?

Source: pexels.com

Studies show that genetics can certainly be a factor when it comes to someone developing bipolar disorder.

According to the Black Dog Institute, approximately 80 percent of all cases of bipolar disorder are hereditary, and if one parent has bipolar disorder, this increases the likelihood of their child developing the condition later in life by approximately 10 percent. [1]

Now, if both parents have the condition, it’s estimated that this increases the odds to 40 percent. [1]

In addition to parents, when taking a look at twin studies, it’s estimated that the chances of both having bipolar disorder could be up to 60 to 80 percent.

These types of statistics show that the odds of someone having bipolar disorder increases based on how close the relative is - people who have a parent or a sibling with the condition are more at risk.

While bipolar disorder does have a hereditary component, it’s important to be aware of it, but not to be alarmed, as genetics do not guarantee that someone will develop the condition at any point in their life, and most of the time, people with immediate family members with bipolar disorder don’t end up getting it themselves. [2]

It is also rare that the disorder affects multiple family members across different generations, and many cases of bipolar disorder are isolated ones. [3]

This means that anyone can theoretically develop bipolar disorder, which is why understanding the other possible causes are important. These other important factors will be discussed later on in the article; however, in the next section, some of the possible genetic mechanisms of bipolar disorder will be covered.

What Genetic Mechanisms Are Responsible For Bipolar Disorder?

While a lot of research has been carried out to try to fully understand the connection that family has with bipolar disorder, a single gene has not been discovered yet that could be the cause of bipolar disorder.

However, there are multiple genes and variations within them that could possibly play a role, in the development of the condition.

In fact, it is believed that the interaction of different genes and various mechanisms, such as dynamic mutation and imprinting, could be the reason for bipolar occurring in the majority of those who are diagnosed with it. [4]

Because of this, it’s also important to note that bipolar disorder doesn’t follow Mendelian genetics, meaning that it doesn’t operate under Gregor Mendel’s laws on the inheritance of traits, such as dominant and recessive alleles, and normally there only two of them, which can be expressed as “A” or “a,” to name an example.

In non-Mendelian inheritance, some of these traits do not segregate, and there can be different types of it, such as co-dominance, incomplete dominance, multiple alleles, or genetic linkage.

While Mendelian inheritance can explain how most traits are passed down, like sex characteristics, eye, skin, and hair color, and the shape of certain facial features, there is always the chance that abnormalities can happen, and the examples of non-Mendelian inheritance mentioned above are ways that it can deviate from the norm.

While there are countless disorders that can be explained through Mendelian inheritance, like sickle cell disease, cystic fibrosis, and Huntington’s disease, non-Mendelian genetics are believed to be responsible for others, like autism spectrum disorder, schizophrenia, and bipolar disorder.

Nonetheless, genetics are not solely the cause for these types of mental health concerns, and in the next section, you will learn about some of the other biological factors that can influence bipolar disorder.

Bipolar and Neurotransmission

Like most mental health issues, bipolar disorder is one that can be linked to neurochemistry. Neurotransmitters, such as serotonin, norepinephrine, and dopamine, are all known to contribute to various disorders such as depression, anxiety, and even schizophrenia, and bipolar disorder can show signs and symptoms that are present in all of these disorders.

Studies show that all of these neurotransmitters may have some involvement in the onset of bipolar disorder.

For example, changes in the serotonergic transportation process could have a role in depressive episodes, just like those who have a major depressive disorder or unipolar depression. Similarly, the noradrenergic system, or norepinephrine, might cause symptoms of bipolar disorder from altered sensitivity at the receptor sites. [5]

Source: pexels.com

Lastly, the dopaminergic system, which has also been linked to schizophrenia, can also be responsible for mood disorders, like bipolar. Unregulated dopamine can cause symptoms seen in both manic and depressive phases, and this is why mood stabilizers, like lithium, work to provide relief for those who have bipolar disorder.

Lithium works to reduce dopaminergic and glutamate activity, and it’s the first-line treatment for bipolar disorder. Antipsychotic medication can also be prescribed to help deal with psychotic symptoms, like delusion and hallucinations, which can be present in both types of episodes.

Medication is necessary in the management of bipolar disorder, and therefore, an assessment and diagnosis must be made by a doctor or mental health professional, such as a psychiatrist, in order to be prescribed medication like lithium.

What Else Can Cause Bipolar Disorder?

In addition to the issues discussed in this article, which can’t be prevented, for the most part, there are other external factors that can be avoided that can contribute to the chemical imbalances that lead to bipolar disorder or make it worse.

For instance, substance abuse can lead to alterations in brain chemistry, and those who have bipolar disorder are more likely to depend on substances to cope with their condition. Addiction is a serious concern and it’s frequently seen in those with the disorder - around 56 percent of individuals with bipolar had struggled with addiction of some sort in their lifetimes, with alcohol being the most common one. [6]

Eating disorders are also prevalent in those who have bipolar disorder, and while the connection between them isn’t as clear as substance abuse, there are different characteristics that eating disorders and bipolar have in common, and they can increase the severity of each other. [7]

Overall, people who have eating disorders may be more prone to mood shifts that are associated with bipolar disorder, because their brain isn’t receiving the nutrition that it needs to function as intended.

People who are dual-diagnosed with substance abuse or eating disorders often are treated concurrently, and while it may be challenging and make treatment more difficult than those who just have a single concern, there are resources available to help people recover, such as rehabilitation programs that are designed for these specific issues.

Therapy For Bipolar Disorder

Source: pexels.com

Although medication is essential in the management of bipolar disorder, it’s typically not enough, and people are also recommended therapy as part of their treatment.

In therapy, people with bipolar disorder can discuss their thoughts, feelings, and emotions that they are struggling with and the challenges that they are facing because of their condition.

A mental health professional will be able to help people learn how to cope with them in healthier and more productive ways, and there are different methods that can help them do this, such as cognitive-behavioral therapy (CBT), interpersonal therapy, and social rhythm therapy.

Individuals with bipolar disorder benefit from learning how to commit to better lifestyle choices, like maintaining a regular sleeping and eating pattern, and therapy can help people establish routines that can make recovery easier.

Therapy can be one-on-one, or it can involve others, including family members who want to get involved with their loved ones and learn how they can provide better support. Group therapy and support groups may also prove to be helpful because it allows patients with bipolar disorder to connect with others who are dealing with similar problems.

Having a strong support system can make it easier for people with bipolar disorder to be consistent with taking medication and avoid unhealthy habits, like substances that can impede recovery.

Do You Or A Loved One Have Bipolar Disorder?

Getting the help that you need for bipolar disorder requires a careful diagnosis from a professional, but recognizing the signs and symptoms can have an important role in taking the first step and reach out to someone who can assist you.

If you think bipolar disorder might be present, you can take this test and find out. It’s brief and it’s completely free, and hopefully, it can encourage you to get started on the path of treatment.

Conclusion

Bipolar disorder is a complex condition that can have different causes, and genetics and biological factors have a significant part in the onset of the condition. Although these issues can’t be avoided, help is available, and the prognosis for people who have bipolar disorder is very positive provided that they have the proper medication and dosages. Management of the condition will be a lifelong endeavor, but people can live happier and happier lives through consistency and commitment.

 References

1. Black Dog Institute. (2020, May 1). Causes of Bipolar Disorder. Retrieved from https://www.blackdoginstitute.org.au/resources-support/bipolar-disorder/causes/

2. Duggal, Neel. “Bipolar Disorder: Is There a Hereditary Connection?” Healthline, Healthline Media, 12 Feb. 2018, www.healthline.com/health/is-bipolar-disorder-hereditary.  

3. Kerner B. (2014). Genetics of bipolar disorder. The application of clinical genetics, 7, 33–42. https://doi.org/10.2147/TACG.S39297

4. Craddock N, Jones I. Genetics of bipolar disorder. Journal of Medical Genetics 1999;36:585-594. Retrieved from: https://jmg.bmj.com/content/36/8/585

5. Manji, H. K., Quiroz, J. A., Payne, J. L., Singh, J., Lopes, B. P., Viegas, J. S., & Zarate, C. A. (2003). The underlying neurobiology of bipolar disorder. World psychiatry: official journal of the World Psychiatric Association (WPA), 2(3), 136–146.

6. Dual Diagnosis. (2020). Bipolar Disorder and Addiction. Retrieved December 18, 2020, from https://dualdiagnosis.org/bipolar-disorder-and-addiction/

7. Thompson, D. (2010, April 20). Eating Disorders and Bipolar Disorder - Bipolar Disorder Center - Everyday Health. Retrieved December 18, 2020, from https://www.everydayhealth.com/bipolar-disorder/eating-disorders-and-bipolar.aspx