What Causes Bipolar Disorder?

Bipolar depression appears to run in families, often affecting someone from every generation, suggesting that some people may inherit a biological vulnerability to the disorder. However, even if genes play an important role in bipolar disorder, it's important to note that many children of bipolar parents do not develop bipolar disorder. Other factors, including life events and stress are just as important. It seems most likely that a combination of several factors causes bipolar disorder including:

• Inherited differences in brain structure and functioning
• Chemical changes in the brain
• Stress and the environment
• A variety of other factors we don't know about yet could also play a role