A population-based longitudinal study of childhood neurodevelopmental disorders, IQ and subsequent risk of psychotic experiences in adolescence. Issue 15 (November 2014)

• Record Type: Journal Article
• Authors: Khandaker, G. M.; Stochl, J.; Zammit, S.; Lewis, G.; Jones, P. B.
• Is Part Of: Psychological medicine. Volume 44:Issue 15(2014)
• Page Start: 3229
• Page End: 3238
• Publication Date: 2014-11
• Subjects: Psychiatry -- Periodicals; Medicine and psychology -- Periodicals; Clinical psychology -- Periodicals; 616.89
• DOI: 10.1017/S0033291714000750
• Languages: English
• ISSNs: 0033-2917

Abstract

<abstract abstract-type="normal"> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <sec id="sec_a1"> <title>Background.</title> <p>Schizophrenia has a neurodevelopmental component to its origin, and may share overlapping pathogenic mechanisms with childhood neurodevelopmental disorders (NDs). Nevertheless, longitudinal studies of psychotic outcomes among individuals with NDs are limited. We report a population-based prospective study of six common childhood NDs, subsequent neurocognitive performance and the risk of psychotic experiences (PEs) in early adolescence.</p> </sec> <sec id="sec_a2" sec-type="methods"> <title>Method.</title> <p>PEs were assessed by semi-structured interviews at age 13 years. IQ and working memory were measured between ages 9 and 11 years. The presence of six NDs (autism spectrum, dyslexia, dyspraxia, dysgraphia, dysorthographia, dyscalculia) was determined from parent-completed questionnaires at age 9 years. Linear regression calculated the mean difference in cognitive scores between children with and without NDs. Associations between NDs and PEs were expressed as odds ratios (ORs) with 95% confidence intervals (CIs); effects of cognitive deficits were examined. Potential confounders included age, gender, father's social class, ethnicity and maternal education.</p> </sec> <sec id="sec_a3" sec-type="results"> <title>Results.</title> <p>Out of 8220 children, 487 (5.9%) were reported to have NDs at age 9 years. Children with, compared with those without, NDs performed worse on all cognitive measures; the adjusted mean difference in total IQ was 6.84 (95% CI 5.00–8.69). The association between total IQ and NDs was linear (<italic>p</italic> < 0.0001). The risk of PEs was higher in those with, compared with those without, NDs; the adjusted OR for definite PEs was 1.76 (95% CI 1.11–2.79). IQ (but not working memory) deficit partly explained this association.</p> </sec> <sec id="sec_a4" sec-type="conclusion"> <title>Conclusions.</title> <p>Higher risk of PEs in early adolescence among individuals with childhood ND is consistent with the neurodevelopmental hypothesis of schizophrenia.</p> </sec> </abstract>