Adults who were born very prematurely experience higher rates of psychiatric symptoms than those who are born at full-term, a study has suggested.
Researchers at King's College London assessed the type and severity of mental health symptoms experienced by adults who were born prematurely using the Comprehensive Assessment of At-Risk Mental States (CAARMS).
They studied 152 adults who were born before 33 weeks' gestation, ranging from 24 to 32 weeks.
They compared these to 96 people born at full-term, considered to be 37 to 40 weeks.
The participants born very preterm showed higher positive, negative, cognitive and behavioural symptoms, including difficulties in concentrating, poor social functioning, delusions and racing thoughts.
The team said their findings support the notion of a direct association between birth factors such as low gestational age and the risk of developing psychiatric disorders later in life.
They suggested those born prematurely may need to be considered a "high-risk" group as adults.
Jasmin Kroll, of the Institute of Psychiatry, Psychology and Neuroscience at King's College London, said: "This new study adds to current knowledge of the long-term consequences of prematurity by showing that a significant proportion of adults who were born prematurely, who may not have mental illnesses severe enough to warrant a diagnosis, continue to have higher than normal levels of mental health symptoms.
"It shows that preterm born adults may need to be considered a 'high-risk' group and that early preventive interventions should extend to very preterm children and adolescents."
Dr Chiara Nosarti, reader of neurodevelopment and mental health at King's College London, said: "For a long time people have known that complications at birth can increase the risk of the child having mental illness when they grow up.
"The discovery of a potential mechanism linking early life risk factors to adult mental illness could one day lead to more targeted and effective treatments of psychiatric problems in people who experienced complications at birth."
The study, which was funded by the Medical Research Council, is published in Psychological Medicine.
