The British Journal of Psychiatry 161: 839-843 (1992)
© 1992 The Royal College of Psychiatrists

Can autism be detected at 18 months? The needle, the haystack, and the CHAT

S Baron-Cohen, J Allen and C Gillberg
Department of Psychology, University of London, De Crespigny Park.

Autism is currently detected only at about three years of age. This study aimed to establish if detection of autism was possible at 18 months of age. We screened 41 18-month-old toddlers who were at high genetic risk for developing autism, and 50 randomly selected 18-month- olds, using a new instrument, the CHAT, administered by GPs or health visitors. More than 80% of the randomly selected 18-month-old toddlers passed on all items, and none failed on more than one of pretend play, protodeclarative pointing, joint-attention, social interest, and social play. Four children in the high-risk group failed on two or more of these five key types of behaviour. At follow-up at 30 months of age, the 87 children who had passed four or more of these key types of behaviour at 18 months of age had continued to develop normally. The four toddlers who had failed on two or more of these key types of behaviour at 18 months received a diagnosis of autism by 30 months.

This article has been cited by other articles:

				S. Shumway and A. M. Wetherby Communicative Acts of Children With Autism Spectrum Disorders in the Second Year of Life J Speech Lang Hear Res, October 1, 2009; 52(5): 1139 - 1156. [Abstract] [Full Text] [PDF]

				K. D. Mraz, J. Dixon, T. Dumont-Mathieu, and D. Fein Accelerated Head and Body Growth in Infants Later Diagnosed With Autism Spectrum Disorders: A Comparative Study of Optimal Outcome Children J Child Neurol, July 1, 2009; 24(7): 833 - 845. [Abstract] [PDF]

				A. V. Snow and L. Lecavalier Sensitivity and specificity of the Modified Checklist for Autism in Toddlers and the Social Communication Questionnaire in preschoolers suspected of having pervasive developmental disorders Autism, November 1, 2008; 12(6): 627 - 644. [Abstract] [PDF]

				S. Ozonoff, S. Macari, G. S. Young, S. Goldring, M. Thompson, and S. J. Rogers Atypical object exploration at 12 months of age is associated with autism in a prospective sample Autism, September 1, 2008; 12(5): 457 - 472. [Abstract] [PDF]

				A. M. Wetherby, S. Brosnan-Maddox, V. Peace, and L. Newton Validation of the Infant--Toddler Checklist as a broadband screener for autism spectrum disorders from 9 to 24 months of age Autism, September 1, 2008; 12(5): 487 - 511. [Abstract] [PDF]

				W. L. Stone, C. R. McMahon, and L. M. Henderson Use of the Screening Tool for Autism in Two-Year-Olds (STAT) for children under 24 months: An exploratory study Autism, September 1, 2008; 12(5): 557 - 573. [Abstract] [PDF]

				J. L. Crane and A. Winsler Early Autism Detection: Implications for Pediatric Practice and Public Policy Journal of Disability Policy Studies, March 1, 2008; 18(4): 245 - 253. [Abstract] [PDF]

				C. P. Johnson, S. M. Myers, and and the Council on Children With Disabilities Identification and Evaluation of Children With Autism Spectrum Disorders Pediatrics, November 1, 2007; 120(5): 1183 - 1215. [Abstract] [Full Text] [PDF]

				K. D. Mraz, J. Green, T. Dumont-Mathieu, S. Makin, and D. Fein Correlates of Head Circumference Growth in Infants Later Diagnosed With Autism Spectrum Disorders J Child Neurol, June 1, 2007; 22(6): 700 - 713. [Abstract] [PDF]

				M. L. Rocha, L. Schreibman, and A. C. Stahmer Effectiveness of Training Parents to Teach Joint Attention in Children With Autism Journal of Early Intervention, January 1, 2007; 29(2): 154 - 172. [Abstract] [PDF]

				W. J. Barbaresi, S. K. Katusic, and R. G. Voigt Autism: A Review of the State of the Science for Pediatric Primary Health Care Clinicians. Arch Pediatr Adolesc Med, November 1, 2006; 160(11): 1167 - 1175. [Abstract] [Full Text] [PDF]

				L. C. Eaves, H. Wingert, and H. H. Ho Screening for autism: Agreement with diagnosis Autism, May 1, 2006; 10(3): 229 - 242. [Abstract] [PDF]

				S. Ozonoff, B. J. Williams, and R. Landa Parental report of the early development of children with regressive autism: The delays-plus-regression phenotype Autism, December 1, 2005; 9(5): 461 - 486. [Abstract] [PDF]

				L. K. Koegel, R. L. Koegel, N. Nefdt, R. Fredeen, E. F. Klein, and Y. E. M. Bruinsma First S.T.E.P: A Model for the Early Identification of Children With Autism Spectrum Disorders Journal of Positive Behavior Interventions, October 1, 2005; 7(4): 247 - 252. [PDF]

				R. C. Tervo Parent's Reports Predict their Child's Developmental Problems Clinical Pediatrics, September 1, 2005; 44(7): 601 - 611. [Abstract] [PDF]

				S. L. Hansson, A. Svanstrom Rojvall, M. Rastam, C. Gillberg, C. Gillberg, and H. Anckarsater Psychiatric telephone interview with parents for screening of childhood autism - tics, attention-deficit hyperactivity disorder and other comorbidities (A-TAC): Preliminary reliability and validity The British Journal of Psychiatry, September 1, 2005; 187(3): 262 - 267. [Abstract] [Full Text] [PDF]

				C. Receveur, P. Lenoir, H. Desombre, S. Roux, C. Barthelemy, and J. Malvy Interaction and imitation deficits from infancy to 4 years of age in children with autism: A pilot study based on videotapes Autism, February 1, 2005; 9(1): 69 - 82. [Abstract] [PDF]

				C. R. Gomez and S. Baird Identifying Early Indicators for Autism in Self-Regulation Difficulties Focus on Autism and Other Developmental Disabilities, January 1, 2005; 20(2): 106 - 116. [Abstract] [PDF]

				A. Alvarez and A. Lee Early Forms of Relatedness in Autism: A Longitudinal Clinical and Quantitative Single-Case Study Clinical Child Psychology and Psychiatry, October 1, 2004; 9(4): 499 - 518. [Abstract] [PDF]

				S. M. Valente Autism Journal of the American Psychiatric Nurses Association, October 1, 2004; 10(5): 236 - 243. [Abstract] [PDF]

				R. P. Goin and B. J. Myers Characteristics of Infantile Autism: Moving ToWard Earlier Detection Focus on Autism and Other Developmental Disabilities, January 1, 2004; 19(1): 5 - 12. [Abstract] [PDF]

				E. A. Jones and E. G. Carr Joint Attention in Children With Autism: Theory and Intervention Focus on Autism and Other Developmental Disabilities, January 1, 2004; 19(1): 13 - 26. [Abstract] [PDF]

				C. Jarrold A Review of Research into Pretend Play in Autism Autism, December 1, 2003; 7(4): 379 - 390. [Abstract] [PDF]

				S. Wieder and S. I. Greenspan Climbing the Symbolic Ladder in the DIR Model Through Floor Time/Interactive Play Autism, December 1, 2003; 7(4): 425 - 435. [Abstract] [PDF]

				E. Courchesne, R. Carper, and N. Akshoomoff Evidence of Brain Overgrowth in the First Year of Life in Autism JAMA, July 16, 2003; 290(3): 337 - 344. [Abstract] [Full Text] [PDF]

				R. L. Young, N. Brewer, and C. Pattison Parental Identification of Early Behavioural Abnormalities in Children with Autistic Disorder Autism, June 1, 2003; 7(2): 125 - 143. [Abstract] [PDF]

				H. Honda and Y. Shimizu Early Intervention System for Preschool Children with Autism in the Community: The Discovery Approach in Yokohama, Japan Autism, September 1, 2002; 6(3): 239 - 257. [Abstract] [PDF]

				S. Chandler, P. Christie, E. Newson, and W. Prevezer Developing a Diagnostic and Intervention Package for 2 to 3-Year-Olds with Autism: Outcomes of the Frameworks for Communication approach Autism, March 1, 2002; 6(1): 47 - 69. [Abstract] [PDF]

				D. A. Charak and J. L. Stella Screening and Diagnostic Instruments for Identification of Autism Spectrum Disorders in Children, Adolescents, and Young Adults: A Selective Review Assessment for Effective Intervention, January 1, 2002; 27(1-2): 5 - 17. [Abstract] [PDF]

				Committee on Children With Disabilities Developmental Surveillance and Screening of Infants and Young Children Pediatrics, July 1, 2001; 108(1): 192 - 195. [Abstract] [Full Text] [PDF]

				Committee on Children With Disabilities Technical Report: The Pediatrician's Role in the Diagnosis and Management of Autistic Spectrum Disorder in Children Pediatrics, May 1, 2001; 107(5): 85e - 85. [Abstract] [Full Text]

				Committee on Children With Disabilities The Pediatrician's Role in the Diagnosis and Management of Autistic Spectrum Disorder in Children Pediatrics, May 1, 2001; 107(5): 1221 - 1226. [Abstract] [Full Text]

				I. Rapin An 8-Year-Old Boy With Autism JAMA, April 4, 2001; 285(13): 1749 - 1757. [Full Text] [PDF]

				T. P. BERNEY Autism -- an evolving concept The British Journal of Psychiatry, January 1, 2000; 176(1): 20 - 25. [Abstract] [Full Text] [PDF]

				J. Malvy, S. Roux, A. Zakian, S. Debuly, D. Sauvage, and C. Barthelemy A Brief Clinical Scale for the Early Evaluation of Imitation Disorders in Autism Autism, December 1, 1999; 3(4): 357 - 369. [Abstract] [PDF]

				P. Vostanis, B. Smith, J. Corbett, R. Sungum-Paliwal, A. Edwards, K. Gingell, R. Golding, A. Moore, and J. Wiilliams Parental Concerns of Early Development in Children with Autism and Related Disorders Autism, September 1, 1998; 2(3): 229 - 242. [Abstract]

				J. Hadwin and G. Hutley Detecting Features of Autism in Thousand Oaks and New Delhi, Children with Severe Learnin Difficulties: A Brief Report Autism, September 1, 1998; 2(3): 269 - 280. [Abstract]

				A. E. O'hare, R. Quew, and K. Aitken The Identification of Autism in Children Referred to a Tertiary Speech and Language Clinic and the Implications for Service Delivery Autism, June 1, 1998; 2(2): 171 - 180. [Abstract]

				T. Charman Specifying the Nature and Course of the Joint Attention Impairment in Autism in the Preschool Years: Implications for Diagnosis and Intervention Autism, March 1, 1998; 2(1): 61 - 79. [Abstract]

				C. Gillberg The psychopharmacology of autism and related disorders J Psychopharmacol, January 1, 1996; 10(1): 54 - 63. [PDF]

				C. Trepagnier A Possible Origin for the Social and Communicative Deficits of Autism Focus on Autism and Other Developmental Disabilities, January 1, 1996; 11(3): 170 - 182. [Abstract] [PDF]

				S. Baron-Cohen and R. Staunton Do children with autism acquire the phonology of their peers? An examination of group identification through the window of bilingualism First Language, January 1, 1994; 14(42-43): 241 - 248. [Abstract] [PDF]