Premature infants face a variety of challenges, including gaining weight, hypothermia and hypoglycemia, and possibly respiratory distress syndrome. Yet there’s another challenge for these babies: the risk of developing mental illnesses.
A new study led by Chiara Nosarti, PhD, of the Department of Psychosis Studies in the Institute of Psychiatry at London’s King’s College, demonstrated that babies born preterm have an elevated risk to develop a range of psychiatric conditions later in life, including psychosis, depression, and bipolar disorder, with bipolar being the highest. Past research has shown that preemies may develop schizophrenia as adults, but little had been studied about bipolar disorder and depression.
Bipolar disorder is a mental illness characterized by “highs” (called mania) and “lows” (called depression). These extreme changes in mood are disruptive to the lives of the individuals who suffer from bipolar disorder.
The scientists pooled data from the Swedish Medical Birth Register for all people born between 1973 and 1985 who were living in Sweden in December, 2000, which totaled 1,301,522 people. The researchers concentrated on the week in which these individuals were born, and looked at whether they had been hospitalized for mental conditions including psychosis, bipolar disorder, and drug and alcohol dependencies.
Preemies born between 32 and 36 weeks were 2.7 times more likely to develop bipolar disorder. They were 1.3 times more likely to develop depressive disorders, and 1.6 times more likely to have nonaffective psychosis.
Younger babies were showed an even stronger association to develop psychiatric conditions. Preemies born before 32 weeks were 7.4 more likely to develop bipolar disorder, 2.5 times more likely for psychosis, and 2.9 times more likely for depression. The infants born before 23 weeks were also more than three times more likely to develop an eating disorder.
However, the scientists did not look at other factors that could contribute to the development of mental illnesses, such as socioeconomic factors, ethnicity, or substance abuse. Another limitation to the study is that the researchers only considered hospitalizations, so milder cases of psychiatric conditions were missed.
The scientists hope that their work will shine a light on preterm infants’ struggles, and that mental illnesses such as bipolar disorder can be more easily diagnosed.