Premature babies at greater risk of mental health disorders

By Margaret Rogers

The media has been awash with news about a new study which suggests that prematurely born babies are at a much higher risk for developing several mental health disorders. These conditions include psychosis, depression, and bipolar disorder.

The research study was conducted by the Institute of Psychiatry at King’s College, London and the Karolinska Institute in Sweden and the study findings are published in the Archives of General Psychology.

The researchers found that babies born very prematurely were three times more likely to need psychiatric treatment when they reach the age of 16 and older, than those who are born at full term. Very premature is considered to be those babies delivered at less than 32 weeks gestation.

The researchers suggest that this increased risk may be because of small differences in brain development if the baby does not reach full-term. The risk was different with each mental health disorder. Premature babies were two and a half times more likely to develop psychosis, three times more likely to develop depression. The most striking risk is that for bipolar disorder which, they suggest, is 7.4 times more likely for babies born before 32 weeks.

The study also found that there is a smaller yet significant increased psychiatric risk for babies who are born only slightly early, at between 32 and 36 weeks.

Chiara Nosarti of the Institute of Psychiatry at King’s College, London said ‘Since we considered only the most severe cases that resulted in hospitalisation, it may be that in real terms this link is even stronger. However, she stressed that ‘the majority of individuals who are born prematurely have no psychiatric or cognitive problems and are completely healthy and well-functioning.’

Nosarti and fellow researchers from the Karolinska Instute analysed data from 1.3 million medical records of Swedish people between 1973 and 1985. They found all the cases of individuals who were admitted to a hospital with their first episode of psychiatric disorder by 2002. They then look back through the records to find whether these individuals had been born either moderately or very prematurely.

Nosarti said ‘The strongest association we found was to mental health disorders known to have a strong biological basis, such as bipolar disorder.

Although earlier research has suggested that premature babies have a greater risk of various health and developmental problems, this is the first study to take an in-depth look at the connection between premature births and the risk of severe psychiatric disorder.

Nosarti was asked whether, with the advancement in medicine which saves the lives of even extremely premature babies, this could account for the rise in mental illness. She said that only a small proportion of these could be explained by premature births.

The overall findings of the study suggest that: