Preterm Birth Is a Risk Factor for Bipolar Disorder
A study published in the Archives of General Psychiatry in 2012 sampled over one million births in Sweden and suggested that preterm birth (from 32 to 36 weeks) doubled the risk that a child would develop bipolar disorder later in life. Those born even earlier had a sevenfold increased risk for bipolar disorder.
Editor’s Note: A robust research literature indicates that schizophrenia is related to obstetrical and other pre- and perinatal medical problems. Now it seems bipolar disorder may be as well, with some caveats. Low Apgar score (which indicates difficulties at birth) and delayed growth were not found to relate to bipolar risk. Thus something about the shortened preterm development seems to convey the risk. The authors suggest that there may be different types of factors that predispose a person to develop bipolar disorder, and that in some people the illness may have development origins.
These data also fit with observations that only about 50% of patients with bipolar disorder have a positive family history of the illness. Thus, while bipolar disorder does run in families and has a strong genetic basis in many instances, there are many people who develop the illness without having this genetic/familial risk. Very preterm birth appears to be one other contributing risk factor, presumably among many others. Understanding the neurobiological mechanisms occurring before birth that mediate this risk may lead to direct preventive measures to lessen the risk. In the meantime, traditional measures supporting good maternal and fetal health are a good place to start. These include regular prenatal checkups, good nutrition, and prenatal vitamins that include high doses of folic acid.
