Do you have bipolar disorder? Or do you know of a relative who was diagnosed with bipolar disorder? What would you do if you learned that bipolar disorder can actually be inherited? Also, if you don’t have bipolar disorder just yet, do you know that you may also be diagnosed sooner or later for unipolar disorder instead? Scary, huh? Now imagine if one of your parents was diagnosed with bipolar disorder; how would you feel?
Family studies show that bipolar disorder tends to run in the family. Around 8 to 9% of first-degree relatives of the person diagnosed with bipolar disorder will also get bipolar disorder. This is 8 to 9 times the rate of prevalence compared to the general population. This potentially suggests that bipolar disorder may run in the genes, and this hypothesis was confirmed by various twin studies conducted on the same topic. But there’s a catch. Although first-degree relatives of a person with bipolar disorder are at higher risk to develop bipolar disorder themselves compared to the general population, the same relatives still have an even higher risk to develop unipolar disorder as well. This could mean that the genetic component of bipolar disorder may well be attributed to mood disorders as a whole. That is, depression, whether bipolar or unipolar, is simply heritable, and that unipolar disorders are just the most common type of depression that manifest in people.
The Family Psychology 