Pre-Term Birth Associated with Higher Risk of Mental Illness, But Also for Siblings

Brian D’Onofrio, Ph.D., of Indiana University Bloomington, brain and behavior research expert
Brian D’Onofrio, Ph.D.

Led by NARSAD Young Investigator Grantee, Brian D’Onofrio, Ph.D. (who was also an Honorable Mention for the Brain & Behavior Research Foundation 2011 Klerman Prize recognizing exceptional clinical research), researchers from Indiana University Bloomington and the Karolinska Institutet in Stockholm examined records of 3.3 million children born in Sweden between 1973 and 2008. Considered to be the largest population-based study of pre-term birth in history, the researchers looked at associations between pre-term birth and mortality, psychological health, educational outcomes and social functioning. These findings were published in Jama Psychiatry on September 25th.

The new study confirmed some beliefs about risks associated with pre-term birth, such as greater risk of mortality, and for developing autism spectrum disorder and attention-deficit hyperactivity disorder. The study, however, also disproves a direct causal relationship between pre-term birth and other mental illnesses, such as schizophrenia or bipolar disorder as well as for suicide attempts.

Using a sibling-comparison approach, the research team found that pre-term birth infants and their siblings had higher chances of developing schizophrenia and bipolar disorder than the general population. The researchers found similar evidence for suicide attempts―pre-term birth infants and their siblings were both equally more likely to attempt suicide.

This suggests, explains Dr. D’Onofrio, Associate Professor in the Department of Psychological and Brain Sciences at Indiana University Bloomington, “that part of the association with severe mental illness and all of the association with suicide isn’t due to pre-term birth; it is due to something else, something that siblings share.”

The problem with previous studies that compared pre-term infants to unrelated non-pre-term infants, but not to their own siblings, D’Onofrio said, “is that pre-term birth is associated with a lot of other factors that are also predictive of poor outcomes in the offspring. So you are not sure if pre-term birth or all these other factors actually cause these harmful outcomes.”

"The study confirms the degree to which pre-term birth is a major public health concern and strongly supports the need for social services that reduce the incidence of pre-term birth," Dr. D'Onofrio went on to say. "Yet, the findings also suggest the need to extend services to all siblings in families with an offspring born pre-term. In terms of policy, it means that the entire family, including all of the siblings, is at risk.”

Learn more about this research.

Read the abstract for this research.