Nature vs. Nurture: Deciphering the Genetic Component of Bipolar Disorder


Bipolar disorder, once known as manic depression, is a mental health condition characterized by extreme mood swings that alternate between episodes of mania and depression. While environmental factors can play a part in the development of the disorder, researchers have found evidence to suggest that genetic factors might also contribute to its onset. In this article, we will explore the nature vs. nurture debate in the context of bipolar disorder and the ways in which genes might influence our susceptibility to the condition.

What is bipolar disorder, and how is it diagnosed?

Bipolar disorder is a condition that affects the brain and can cause sudden and extreme shifts in mood, energy and activity levels. Individuals with bipolar disorder experience periods of mania (or hypomania) characterized by elevated moods, excessive energy, and racing thoughts, followed by periods of depression that leave them feeling sad, hopeless, and lethargic. There are two types of bipolar disorder: Bipolar I disorder, which involves manic episodes lasting at least seven days or being so severe that hospitalization is necessary, and Bipolar II disorder, which involves hypomanic episodes and severe depressive episodes.

To diagnose bipolar disorder, a healthcare professional might ask the person about their mood patterns and ask them to describe how they are feeling. A mental health assessment is also necessary to rule out other conditions like depression or anxiety disorders, which can have similar symptoms.

What causes bipolar disorder?

It is challenging to pinpoint a single cause of bipolar disorder; instead, a range of environmental and genetic factors may put individuals at higher risk. Environmental factors could include things like prolonged stress, risky drug or alcohol use, a history of trauma, or poor sleep habits. Equally, there might also be a genetic component to the disorder as studies have found that individuals with a family member who has bipolar disorder are more likely to develop the condition.

What do we know about the genetic component of bipolar disorder?

Research has shown that there could be several genes that contribute to the development of bipolar disorder. A 2019 scientific review found that genetics accounts for around 60-80% of a person’s risk of developing the disorder, which suggests that there is a considerable genetic component to the condition.

One gene that has caught the attention of researchers is the COMT gene, which is involved in the regulation of dopamine in the brain. Dopamine is a neurotransmitter that plays a role in regulating mood, and evidence suggests that imbalances in dopamine levels could contribute to the onset of bipolar disorder. Changes to the COMT gene have been found to be associated with an increased risk of bipolar disorder, but it is not yet possible to use genetics as a definitive marker for the disorder.

It is essential to note that genetics and environmental factors could interact in complex ways, which means that having certain genes does not necessarily cause bipolar disorder but may make some people more susceptible to it under specific circumstances.

What are the implications of the genetic component of bipolar disorder?

Understanding the genetic component of bipolar disorder has several implications for healthcare professionals and individuals with the condition. Genetics research could lead to more accurate diagnoses of the disorder by allowing healthcare professionals to identify people at higher risk of developing bipolar disorder before symptoms emerge.

Additionally, the genetic component of bipolar disorder could help to identify new treatments for the condition by providing targets for new therapies. For example, researchers could use gene-editing techniques to alter the genes responsible for bipolar disorder, although it is still in the early stages of development.

In conclusion, while the causes of bipolar disorder are still not fully understood, researchers agree that the condition is the result of a combination of genetic and environmental factors. A greater understanding of how genes influence bipolar disorder could eventually lead to new treatments that target the underlying genetic causes of the disorder.