Low birth weight babies are at greater risk of developing psychosis-like
symptoms as they grow up, research suggests. The study, published in the June
issue of the British Journal of Psychiatry, shows a link between children's size
at birth and their mental health at the age of 12.
Researchers from the University of Bristol assessed 6,000 12-year-old
children to find out if they had experienced any hallucinations or delusions
over the last 6 months.
Of the 6,000 children, 820 (13%) had experienced at least one psychotic
symptom. These included visual and auditory hallucinations, and delusions of
being spied upon, persecuted or having their thoughts read.
All the children had been followed since birth as part of the Avon Longitudinal Study of Parents and Children (ALSPAC). This
allowed the researchers to analyse their birth weights, birth length and growth
The researchers found strong evidence that babies born with a low birth
weight and short birth length were at increased risk of psychosis-like symptoms
at 12 years of age. A one standard deviation increase in birth weight was
associated with an 18% reduction in the risk of psychosis-like symptoms.
There was no evidence of a link between the children's growth during their
early childhood, and psychotic symptoms at the age of 12.
The study findings echo previous research suggesting that a low birth weight
is associated with an increased risk of schizophrenia in later life.