A recent study published in the Archives of General Psychiatry found a relationship between gestational age and various psychiatric disorders in adults. The results suggest that a concrete relationship exists between a shorter gestational period and the onset of mental illness later in life.

The study analyzed data from the medical records of 1.3 million adults born in Sweden between 1973 and 1985. Researchers analyzed multiple pregnancy outcomes including gestational age at birth, birth weight, and Apgar score; they then compared this data with information about psychiatric hospitalization in adulthood and diagnoses of bipolar disorder, depressive disorder, eating disorders, and drug/alcohol dependency.

A smaller gestational weight was associated with alcohol and drug dependency in adulthood, whereas a low Apgar score suggested an association with depressive disorder. Most strikingly, people born very premature (i.e., 32 weeks gestation) were:

• 2.5 times more likely to have a non-affective psychosis;


• 2.9 times more likely to have a depressive disorder; and


• 7.4 times more likely to have bipolar disorder.

Lead author Dr. Chiara Nosarti, from the Institute of Psychiatry at King’s College London, told the BBC, “I don’t think parents should be worried, but we know that preterm birth confers an increased vulnerability to a variety of psychiatric conditions and perhaps parents should be aware of this and monitor early signs of later more serious problems.”

Although Nosarti and her coauthors acknowledge that previous studies have found associations between preterm birth and the onset of psychiatric disorders in childhood as well as adult onset schizophrenia, they assert that this study is the first to find an association between preterm birth and adult onset of both depressive disorder and bipolar affective disorder.

“We found a very strong link between premature birth and a range of psychiatric disorders,” said Nosarti in a King’s College press release. “Since we considered only the most severe cases that resulted in hospitalization, it may be that in real terms this link is even stronger. However, it is important to remember that even with the increased risk, these disorders still only affect 1-6% of the population.”

What do you think? Should parents of premature infants be alerted to their children’s increased risk for mental illness later in life? PAR wants to hear from you, so leave a comment and join the conversation!

Editor’s note: This week, PAR is pleased to welcome guest blogger Grace Gardner. A recent graduate of the University of South Florida with a B.A. in Mass Communication, Grace is working as an editorial assistant this summer in the production department at PAR.

According to an eleven-year-long study by a group of Canadian researchers, it appears that the youngest students in a class are more likely to be diagnosed with attention deficit hyperactivity disorder (ADHD) than peers born at other points in the year.

The study, conducted by University of British Columbia researchers and headed up health research analyst Richard Morrow, finds that children born the month of the school’s cut-off date were more likely to receive an ADHD diagnosis than those born just a month later. After studying nearly 930,000 children in British Columbia, which has a cut-off date for enrollment of December 31, it was found that boys born in December were 30 percent more likely to be given an ADHD diagnosis than those born in January. Girls with December birthdays were 70 percent more likely to receive this diagnosis than those born in January. Furthermore, boys and girls with December birthdays were 41 percent and  77 percent more likely, respectively, to be treated with prescription medication for ADHD than those born the following month.

While researchers believe their analyses show a relative-age effect in the diagnosis and treatment of children age 6-12 years, they warn that these findings raise concerns about the potential for overdiagnosis and overprescribing in the youngest students because the lack of maturity in younger students may be misinterpreted as symptoms of ADHD. ADHD is currently the most commonly diagnosed neurobehavioral disorder in children.

For more information on this study, visit the Canadian Medical Association Journal.