Is bipolar genetic?

Bipolar disorder and genetics

The chances of inheriting bipolar disorder are unclear.

Although it is inarguable that genetic factors have a role in its development ^[2], it is a mental disorder that may or may not be passed down because its transference is ‘polygenic’. This means that it is controlled by various genes making it very complex.

Bipolar disorder is the result of a combination of genes, which, when combined, make the chances of developing the mental health condition more likely. Some genetic studies maintain that bipolar disorder may be caused by ‘irregularities’ in certain genes, not just the combination of genes ^[1].

So, is bipolar disorder genetic?

Research tells us that bipolar disorder can be caused by environmental factors or ‘triggers’ that can provoke the condition in someone who is genetically predisposed to it ^[3].

A trigger is specific to the individual and can range from any number of universal human experiences, such as

• Grief, or the loss of someone close to you
• A traumatic life event, an accident, or a violent experience like rape or assault
• A period of high stress
• The loss of a job or the beginning of another
• The breakdown of a relationship
• For someone who already has a history of major depression or schizophrenia,the possibility of developing bipolar disorder is higher
• At a moment of transition in life

But for bipolar patients who worry about becoming a parent - there is not a single gene or gene sequence which guarantees a child will be born with bipolar disorder ^[2].

According to research, though the diagnosis is more likely, the certainty of direct inheritance remains unpredictable. Children with one parent with the medical condition have a 10-25% chance of developing it; while children born of a couple with the psychiatric disorder statistically have a 20-50% chance of experiencing it themselves ^[1]. Nonetheless, studies generally concur that people diagnosed with bipolar disorder have at least one first-degree relative with major depressive disorder or bipolar disorder.

For those who are already the parent of one child who has bipolar disorder, there is a 50-70% chance that your second child will have it too ^[2].  

It is important to note that as our understanding of genetics and medicine has advanced, so has our awareness of the possibility that the response people have to certain medications used in treating mental health disorders could also be influenced by our genes. It is worth discussing these factors with your doctor or medical professional before embarking on a course of treatment ^[4].

What other causes of bipolar disorder are there?

Though people with a relative diagnosed with bipolar disorder are more likely to be diagnosed with it themselves, the disorder’s development is often provoked by the misuse or abuse of alcohol or drugs.

Research tells us that 50% of all patients with bipolar disorder have substance or alcohol abuse problems ^[5]. Childbirth has also been linked to first-time psychiatric experiences or disorders. Bipolar disorder can equally be aggravated by lack of sleep.

Many people from different backgrounds experience bipolar disorder. For example, it is believed 2.8% of U.S. adults experience bipolar disorder at least once in any given year and that as much as 4.4% of people will experience it at some point in their lives.