Bipolar Disorder — Genetics and Contributing Factors

Based in Chevy Chase, MD, psychiatrist David Chen, MD, previously served as a clinical research fellow at the National Institutes of Health. Throughout his career, Dr. David Chen has focused on the genetics of bipolar disorder. His accomplishments include discovering the TRANK1, LMAN2L, and PTGFR bipolar risk genes.

While the exact causes of bipolar disorder aren’t well-understood, Dr. Chen and other researchers have found that certain gene variations passed through families increase a person’s chances of developing the disorder. According to the National Institute of Mental Health, bipolar disorder occurs in an estimated 2.8 percent of American adults each year.

Research suggests that those with a close relative with the condition have a 5–10 percent chance of developing it themselves in their lifetime. This risk increases significantly to 40–70 percent for twins. Although this clearly shows a genetic connection, the role that genes play in the disorder isn’t fully understood. It’s likely that while genetic disposition is a contributing factor, other factors combine to trigger its development.

Some other bipolar causes and risk factors include brain structure, alcohol and drug use, and traumatic head injury. Various environmental factors can also trigger the onset of the disorder. These include sudden major life changes, such as a death in the family, and even seasonal changes and lacking sleep.