TY - JOUR
T1 - IQ and non-clinical psychotic symptoms in 12-year-olds
T2 - results from the ALSPAC birth cohort
AU - Horwood, J.
AU - Salvi, G.
AU - Thomas, K.
AU - Duffy, L.
AU - Gunnell, D.
AU - Hollis, Chris
AU - Lewis, Glyn H
AU - Menezes, P.
AU - Thompson, A.
AU - Wolke, D.
AU - Zammit, Stanley
AU - Harrison, G.
N1 - Publisher: Royal College of Psychiatrists
PY - 2008/9/1
Y1 - 2008/9/1
N2 - BACKGROUND: Non-clinical psychotic symptoms appear common in children, but it is possible that a proportion of reported symptoms result from misinterpretation. There is a well-established association between pre-morbid low IQ score and schizophrenia. Psychosis-like symptoms in children may also be a risk factor for psychotic disorder but their relationship with IQ is unclear. AIMS: To investigate the prevalence, nature and frequency of psychosis-like symptoms in 12-year-old children and study their relationship with IQ. METHOD: Longitudinal study using the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. A total of 6455 children completed screening questions for 12 psychotic symptoms followed by a semi-structured clinical assessment. IQ was assessed at 8 years of age using the Wechsler Intelligence Scale for Children (3rd UK edition). RESULTS: The 6-month period prevalence for one or more symptoms was 13.7% (95% CI 12.8-14.5). After adjustment for confounding variables, there was a non-linear association between IQ score and psychosis-like symptoms, such that only those with below average IQ score had an increased risk of reporting such symptoms. CONCLUSIONS: Non-clinical psychotic symptoms occur in a significant proportion of 12-year-olds. Symptoms are associated with low IQ and also less strongly with a high IQ score. The pattern of association with IQ differs from that observed in schizophrenia.
AB - BACKGROUND: Non-clinical psychotic symptoms appear common in children, but it is possible that a proportion of reported symptoms result from misinterpretation. There is a well-established association between pre-morbid low IQ score and schizophrenia. Psychosis-like symptoms in children may also be a risk factor for psychotic disorder but their relationship with IQ is unclear. AIMS: To investigate the prevalence, nature and frequency of psychosis-like symptoms in 12-year-old children and study their relationship with IQ. METHOD: Longitudinal study using the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. A total of 6455 children completed screening questions for 12 psychotic symptoms followed by a semi-structured clinical assessment. IQ was assessed at 8 years of age using the Wechsler Intelligence Scale for Children (3rd UK edition). RESULTS: The 6-month period prevalence for one or more symptoms was 13.7% (95% CI 12.8-14.5). After adjustment for confounding variables, there was a non-linear association between IQ score and psychosis-like symptoms, such that only those with below average IQ score had an increased risk of reporting such symptoms. CONCLUSIONS: Non-clinical psychotic symptoms occur in a significant proportion of 12-year-olds. Symptoms are associated with low IQ and also less strongly with a high IQ score. The pattern of association with IQ differs from that observed in schizophrenia.
UR - http://orca.cf.ac.uk/81977/
U2 - 10.1192/bjp.bp.108.051904
DO - 10.1192/bjp.bp.108.051904
M3 - Article (Academic Journal)
SN - 0007-1250
VL - 193
SP - 185
EP - 191
JO - British Journal of Psychiatry
JF - British Journal of Psychiatry
IS - 3
ER -