Children who have brains that process information more slowly are at a greater risk of psychotic experiences, according to a study by experts from Bristol and Cardiff universities.
Schizophrenia is a complex and relatively rare mental health condition
The episodes may include hearing voices, seeing things that are not there or holding unrealistic beliefs and can be “distressing and frightening”.
Research has previously shown youngsters with such experiences are more likely to develop psychotic illnesses in later life.
Experts from the two universities examined cognitive test scores of 6,784 children aged eight, 10 and 11, then examined whether the result was linked to psychotic episodes aged 12.
They found children who performed poorly in the tests – which assessed information processing speed, attention, memory, reasoning and problem solving skills – were at greater risk of the experiences.
Children whose brain processing speed slowed between the ages of eight and 11 were even more likely to suffer psychotic episodes.
The findings did not change when other factors, such as their parents’ psychiatric history and own developmental delay, were taken into account.
It is hoped the results of the study could help identify children at risk of psychosis, allowing them to benefit from early treatment.
Maria Niarchou, lead author and PhD student from Cardiff University’s School of Medicine, said: “Previous research has shown a link between the slowing down of information processing and schizophrenia and this was found to be at least in part the result of anti-psychotic medication.
“However, this study shows that impaired information processing speed can already be present in childhood and associated with higher risk of psychotic experiences, irrespective of medication.
“Our findings improve our understanding of the brain processes that are associated with high risk of psychotic experiences in childhood and in turn high risk of psychotic disorder later in life.”
Researchers from the School of Social and Community Medicine at the University of Bristol and the MRC Centre for Neuropsychiatric Genetics and Genomics at Cardiff University used data gathered from 6,784 participants in the Children of the 90s study.
The Children of the 90s, also known as the Avon Longitudinal Study of Parents and Children (ALSPAC), is a research project which enrolled 14,000 pregnant women between 1991 and 1992 and has been monitoring the health and development of parents and children ever since.
Of the 6,784 children in the recent study, 787 – or 11.6 per cent – were suspected of definite psychotic experiences aged 12.
Children that scored less well in the various tests at ages eight, 10 and 11 were more likely to suffer the episodes.
The link was particularly noticeable in the test that measured how quickly the children could process information.
In addition, children whose processing speed decreased between the ages of eight and 11 had greater risk of having psychotic experiences aged 12.
Dr Marianne van den Bree, of Cardiff University’s School of Medicine, added: “Schizophrenia is a complex and relatively rare mental health condition, occurring at a rate of one per cent in the general population.
“Not every child with impaired information processing speed is at risk of psychosis later in life.
“Further research is needed to determine whether interventions to improve processing speed in at-risk children can lead to decreased transition to psychotic disorders.”
Ruth Coombs, manager for influence and change at Mind Cymru, said: “This is a very interesting piece of research, which could help young people at risk of developing mental health problems in later life build resilience and benefit from early intervention.
“It is important to remember that people can and do recover from mental health problems and we also welcome further research which supports resilience building in young people.”
The paper is published in the American Journal of Psychiatry.