American Psychiatric Association (1994) Diagnostic and Statistical Manual of Mental Disorders (4th edn) (DSM–IV). Washington, DC: APA.
Bailey, A., Le Couteur, A., Gottesman, I., et al (1995) Autism as a strongly genetic disorder: evidence from a British twin study. Psychological Medicine, 25, 63–77.
Berument, S. K., Rutter, M., Lord, C., et al (1999) Autism screening questionnaire: diagnostic validity
British Journal of Psychiatry, 175, 444–451.
Chakrabarti, S. & Fombonne, E. (2001) Pervasive developmental disorders in preschool children. JAMA, 285, 3093–3099.
Charman, T., Baron-Cohen, I., Baird, G., et al (2001) Commentary: the Modified Checklist for Autism in Toddlers. Journal of Autism and Developmental Disorders, 31, 145–148.
Cohen, I. L., Schmidt-Lackner, S., Romanczyk, R., et al (2003) The PDD Behavior Inventory: a rating scale for assessing response to intervention in children with pervasive developmental disorder. Journal of Autism and Developmental Disorders, 33, 31–45.
Constantino, J. N. & Todd, R. D. (2003) Autistic traits in the general population: a twin study. Archives of General Psychiatry, 60, 524–530.
Constantino, J. N., Davis, S. A., Todd, R. D., et al (2003) Validation of a brief quantitative measure of autistic traits: comparison of the social responsiveness scale with the autism diagnostic interview – revised. Journal of Autism and Developmental Disorders, 33, 427–433.
Ehlers, S., Gillberg, C. & Wing, L. (1999) A screening questionnaire for Asperger syndrome and other high functioning autism spectrum disorders in school age children. Journal of Autism and Developmental Disorders, 29, 129–141.
Fombonne, E. (1991) The use of questionnaires in child psychiatry research: measuring their performance and choosing an optimal cut-off. Journal of Child Psychology and Psychiatry, 32, 677–693.
Geurts, H. M., Verte, S., Oosterlaan, J., et al (2004) Can the Children's Communication Checklist differentiate between children with autism, children with ADHD, and normal controls?
Journal of Child Psychology and Psychiatry, 45, 437–453.
Gilmour, J., Hill, B., Place, M., et al (2004) Social communication deficits in conduct disorder: a clinical and community survey. Journal of Child Psychology and Psychiatry, 45, 967–978.
Lord, C., Rutter, M. & LeCouteur, A. (1994) Autism Diagnostic Interview – Revised: a revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. Journal of Autism and Developmental Disorders, 24, 659–685.
Lord, C., Risi, S., Lambrecht, L., et al (2000) The Autism Diagnostic Observation Schedule – Generic: a standard measure of social and communication deficits associated with the spectrum of autism. Journal of Autism and Developmental Disorders, 30, 205–223.
Medical Research Council (2001) MRC Review of Autism Research: Epidemiology and Causes. London: MRC.
Scott, F. J., Baron-Cohen, S., Bolton, P., et al (2002) The CAST (Childhood Asperger Test): preliminary development of a UK screen for mainstream primary-school age children. Autism, 6, 9–31.
Scourfield, J., Martin, N., Lewis, G., et al (1999) Heritability of social cognitive skills in children and adolescents. British Journal of Psychiatry, 175, 559–564.
Scourfield, J., Martin, N., Eley, T. C., et al (2004) The genetic relationship between social cognition and conduct problems. Behavioral Genetics, 34, 377–383.
Silverman, J. M., Smith, C. J., Schmeidler, J., et al (2002) Symptom domains in autism and related conditions: evidence for familiality. American Journal of Medical Genetics, 114, 64–73.
Skuse, D. H., James, R. S., Bishop, D. V., et al (1997) Evidence from Turner's syndrome of an imprinted X-linked locus affecting cognitive function. Nature, 387, 705–708.
Skuse, D., Warrington, R., Bishop, D., et al (2004) The developmental, dimensional and diagnostic interview (3di): a novel computerized assessment for autism spectrum disorders. Journal of the American Academy of Child and Adolescent Psychiatry, 43, 548–558.
South, M., Williams, B. J., McMahon, W. M., et al (2002) Utility of the Gilliam Autism Rating Scale in research and clinical populations. Journal of Autism and Developmental Disorders, 32, 593–599.
Spiker, D., Lotspeich, L. J., Dimiceli, S., et al (2002) Behavioral phenotypic variation in autism multiplex families: evidence for a continuous severity gradient. American Journal of Medical Genetics, 114, 129–136.
Tamhane, A. C. (1979) A comparison of procedures for multiple comparisons of means with unequal variances. Journal of the American Statistical Association, 74, 471–480.
Volkmar, F. R., Lord, C., Bailey, A., et al (2004) Autism and pervasive developmental disorders. Journal of Child Psychology and Psychiatry, 45, 135–170.
Wechsler, D. (1992) Wechsler Intelligence Scale for Children (3rd UK edn). London: Psychological Corporation.
World Health Organization (1992) International Statistical Classification of Diseases and Related Health Problems (ICD – 10). Geneva: WHO.
Yeargin-Allsopp, M., Rice, C., Karapurkar, T., et al (2003) Prevalence of autism in a US metropolitan area. JAMA, 289, 49–55.