Causes of Bipolar Disorder
Genetics
Bipolar disorder is a condition that can be passed through genetics. Studies have found that individuals have anywhere from five to ten times higher likelihood of developing Bipolar disorder from their first-degree relatives in comparison to the general population (Swartz & Suppes, 2019). First-degree relatives include individuals who share around half of their genetics with you, such as your parents, siblings, and offspring. Additionally, a 2018 study found that the percentage of Bipolar diagnoses from genetics was 41% for Bipolar I and 36% for Bipolar II (Parker et al., 2018, as cited in Swartz & Suppes, 2019). While researchers have found there is a genetic component to Bipolar disorder, they are working to determine what specific gene or gene combinations are responsible for an individual’s exposure to the disorder. It is important to note, however, that even if a person's first-degree relative has Bipolar disorder, there is a likelihood that they won't develop the disorder themselves.
Trauma and Stress
Along with genetics, traumatic life events and stress are some of the most common causes of individuals developing Bipolar disorder. Multiple studies have determined that childhood trauma can cause individuals to develop Bipolar disorder. In fact, approximately half of individuals diagnosed with Bipolar disorder have reported a history of childhood trauma (Aldinger and Schulze, 2017). Any kind of trauma, including physical, emotional, and sexual, can influence a person’s chance of having the disorder. In addition, trauma or other extreme life stressors can result in individuals developing Bipolar at an earlier age (Post and Miklowitz, 2010). Additionally, if someone does not have strong coping skills to manage their stress, it can also impact their likelihood of developing the disorder.
Alcohol and Drug Abuse
Abuse of drugs and alcohol can increase a person’s likelihood of developing Bipolar disorder. Excessive long-term use of drugs and alcohol, as found by the International Bipolar Foundation, is shown to permanently change the structures of a person’s brain. These changes, as a result, can have a significant impact on a person's mood and behavior (Crain, 2024). Not only that, but drug and alcohol abuse can worsen a person’s symptoms and the frequency of their episodes.
Previous Medical Conditions
One review article found that there is a relationship between intrauterine infections and the onset of psychological disorders, including Bipolar disorder (Aldinger and Schulze, 2017). Intrauterine infections are a type of infection that takes place during pregnancy, impacting both the mother and her child. For the child specifically, intrauterine infections can impact their brain development both inside and outside of the womb. As a result, there is a possibility the child’s psychological health can be impaired, leaving them at risk of developing a psychological disorder such as Bipolar disorder (Aldinger and Schulze, 2017). Additionally, there is evidence that some viral infections during adulthood, such as influenza B, can put individuals at risk of developing Bipolar disorder (Aldinger and Schulze, 2017). However, there are few studies that support these findings, which has cast doubt among researchers regarding the validity of these findings.