Child literacy and psychotic experiences in early adolescence: Findings from the ALSPAC study Mohajer A. Hameed a , Andrew J. Lewis a, ⁎, Sarah Sullivan b , Stanley Zammit b, c a School of Psychology, Faculty of Health, Deakin University, Melbourne, Australia b The Academic Unit of Psychiatry, School of Social and Community Medicine, University of Bristol, Bristol, UK c MRC Centre for Neuropsychiatric Genetics & Genomics, Cardiff University, Cardiff, UK abstract article info Article history: Received 22 August 2012 Received in revised form 10 December 2012 Accepted 23 December 2012 Available online 6 February 2013 Keywords: Child literacy Psychotic experiences Schizophrenia Prevention ALSPAC The aim of this study was to use prospective data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to examine the differences in literacy skills in children who later completed the psychotic like symptoms (PLIKS) interview at 12 years of age. We further examined the association between literacy skills over time in relation to the likelihood of reporting psychotic experiences (PEs). This study examined data from n = 6790 children from the ALSPAC cohort who participated in the PLIKS semi-structured interview. Literacy skills such as spelling, basic real and non-real word reading, and reading skills and comprehension were assessed by an ALSPAC spelling task, Wechsler Objective Reading Dimension, and the revised Neale Analysis of Reading Ability (NARA II) respectively. Relative to the group unaffected by PEs, we found a lower performance in all measurements of child literacy skills in those with suspected or definite PEs. The majority of these differences persisted after adjusting for a range of covariates. In addition, both a consistent- ly low pattern of performance and a decline were associated with suspected or definite PEs. Implications for preventative intervention models focussed on children at risk of developing psychotic disorders are discussed within the context of speech and language development. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Given the clear relationship between psychotic symptoms and linguistic functioning, there is a longstanding interest in the develop- ment of speech and language abilities in children who go on to devel- op schizophrenia. While a number of prospective cohort studies have examined various aspects of linguistic competence across develop- ment as predictors of psychotic disorders, findings have been equivo- cal (Jones et al., 1994; Done et al., 1998; Bearden et al., 2000; Isohanni et al., 2001; Cannon et al., 2002; Welham et al., 2010). This paper draws on data from a population cohort study to examine the predic- tion of psychotic-like symptoms assessed at the mean age of 12 years by childhood performance on literacy tasks. A number of researchers have suggested that aberrant and de- layed speech development could be a factor that contributes particu- larly to the development of verbal hallucinations (McGuire and Shah, 1993; Jones et al., 1994). In addition, formal thought disorder, a key diagnostic feature of the disorder (Bleuler, 1950), shows clear linguis- tic features. Thought disorder in the context of schizophrenia is apparent in joining semantically or phonologically similar words and in semantic anomalies such as tangentially slipping from one topic to another (Andreasen et al., 1998). Negative symptoms of schizophrenia also have linguistic features such as lack of verbal initi- ation and poverty of speech content. Some time ago, Jones and col- leagues proposed that subtle differences in the development of linguistic competence may contribute to the development of schizo- phrenia, but cautioned that language would be best considered as one component of a complex and multi-factored process that unfolds over time (1994). To date, six cohort studies have examined the association between some aspect of speech and language development in childhood and the onset of psychotic disorders in adulthood. Jones et al. (1994) reported that children who later developed schizophrenia were found to have subtle verbal and non-verbal speech differences by the age of 2, and up to age 15, were more likely to have speech prob- lems. However, the individuals with schizophrenia did not differ from normal controls on measures of literacy skills such as reading when assessed at ages 8, 11, and 15 years. Bearden et al. (2000) explored childhood language abnormalities as predictors of adult schizophre- nia and showed that after controlling for covariates (ethnicity, gen- der, parental education and socioeconomic status, and age at time of examination), abnormal speech at age 7 (assessed by a speech pa- thologist) was a significant predictor of schizophrenia with a greater than 12 fold increase (95% CI = 2.46–65.66) in risk. Similarly, perfor- mance at age 7 on the Auditory–Vocal Association Test that assesses Schizophrenia Research 145 (2013) 88–94 ⁎ Corresponding author at: Research Academic in Clinical Psychology, School of Psychology, Faculty of Health, Deakin University, 221 Burwood Hwy., Burwood, VIC 3125, Australia. Tel.: +61 3 9244 6774. E-mail address: andrew.lewis@deakin.edu.au (A.J. Lewis). 0920-9964/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.schres.2012.12.025 Contents lists available at SciVerse ScienceDirect Schizophrenia Research journal homepage: www.elsevier.com/locate/schres