1. Top of page
  2. Abstract
  3. References

Rates of diagnosis of autism have risen since 1980, raising the question of whether some children who previously had other diagnoses are now being diagnosed with autism. We applied contemporary diagnostic criteria for autism to adults with a history of developmental language disorder, to discover whether diagnostic substitution has taken place. A total of 38 adults (aged 15–31y; 31 males, seven females) who had participated in studies of developmental language disorder during childhood were given the Autism Diagnostic Observation Schedule - Generic. Their parents completed the Autism Diagnostic Interview - Revised, which relies largely on symptoms present at age 4 to 5 years to diagnose autism. Eight individuals met criteria for autism on both instruments, and a further four met criteria for milder forms of autistic spectrum disorder. Most individuals with autism had been identified with pragmatic impairments in childhood. Some children who would nowadays be diagnosed unambiguously with autistic disorder had been diagnosed with developmental language disorder in the past. This finding has implications for our understanding of the epidemiology of autism.

List of abbreviations:

Autism Diagnostic Interview - Revised


Autism Diagnostic Observation Schedule - Generic


Autistic spectrum disorder


Pragmatic language impairment


Specific language impairment


  1. Top of page
  2. Abstract
  3. References
  • 1
    Williams JG, Higgins JPT, Brayne CEG. Systematic review of prevalence studies of autism spectrum disorders. Arch Dis Child 2006; 91: 815.
  • 2
    Rutter M. Incidence of autism spectrum disorders: changes over time and their meaning. Acta Paediatr 2005; 94: 215.
  • 3
    Bishop DVM. Autism, Asperger's syndrome and semantic-pragmatic disorder: where are the boundaries? Br J Disord Commun 1989; 24: 10721.
  • 4
    Bishop DVM, Norbury CF. Exploring the borderlands of autistic disorder and specific language impairment: a study using standardised diagnostic instruments. J Child Psychol Psychiatry 2002; 43: 91729.
  • 5
    Boucher J. SPD as a distinct diagnostic entity: logical considerations and directions for future research. Int J Lang Commun Disord 1998; 33: 7181.
  • 6
    Botting N. Semantic–pragmatic disorder (SPD) as a distinct diagnostic entity: making sense of the boundaries. Int J Lang Commun Disord 1998; 33: 8790.
  • 7
    Brook SL, Bowler DM. Autism by another name? Semantic and pragmatic impairments in children. J Autism Dev Disord 1992; 22: 6181.
  • 8
    Bishop DVM, Rosenbloom L. Classification of childhood language disorders. In: W.Yule, Rutter M, eds. Language development and disorders. Clinics in Developmental Medicine No. 101/102. London : Mac Keith Press, 1987: 1641.
  • 9
    Rapin I, Allen D. Developmental language disorders: nosologic considerations. In: KirkU, ed. Neuropsychology of language, reading, and spelling. New York : Academic Press, 1983: 15584.
  • 10
    Bishop DVM. Development of the Children's Communication Checklist (CCC): a method for assessing qualitative aspects of communicative impairment in children. J Child Psychol Psychiatry 1998; 39: 87991.
  • 11
    Conti-Ramsden G, Crutchley A, Botting N. The extent to which psychometric tests differentiate subgroups of children with SLI. J Speech Lang Hear Res 1997; 40: 76577.
  • 12
    Lord C, Risi S, Lambrecht L, et al. The Autism Diagnostic Observation Schedule - Generic: a standard measure of social and communication deficits associated with the spectrum of autism. J Autism Dev Disord 2000; 30: 20523.
  • 13
    Lord C, Rutter M, LeCouteur A. Autism Diagnostic Interview – Revised: a revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. J Autism Dev Disord 1994; 24: 65985.
  • 14
    Risi S, Lord C, Gotham K, et al. Combining information from multiple sources in the diagnosis of autism spectrum disorders. J Am Acad Child Adolesc Psychiatry 2006; 45: 1094103.
  • 15
    American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 3rd edn (revised DSM-III-R, 1987). Washington DC : APA, 1980.
  • 16
    Baird G, Simonoff E, Pickles A, et al. Prevalence of disorders of the autism spectrum in a population cohort of children in South Thames: the Special Needs and Autism Project (SNAP). Lancet 2006; 368: 21015.
  • 17
    Jick H, Kaye JA. Epidemiology and possible causes of autism. Pharmacotherapy 2003; 23: 152430.
  • 18
    Shattuck PT. The contribution of diagnostic substitution to the growing administrative prevalence of autism in US special education. Pediatrics 2006; 117: 102837.
  • 19
    Conti-Ramsden G, Simkin Z, Botting N. The prevalence of autistic spectrum disorders in adolescents with a history of specific language impairment (SLI). J Child Psychol Psychiatry 2006; 47: 62128.
  • 20
    Howlin P, Mawhood L, Rutter M. Autism and developmental receptive language disorder - a comparative follow-up in early adult life. II. Social, behavioural, and psychiatric outcomes. J Child Psychol Psychiatry 2000; 41: 56178.
  • 21
    Clegg J, Hollis C, Mawhood L, Rutter M. Development language disorders - a follow-up in later life. Cognitive, language and psychosocial outcomes. J Child Psychol Psychiatry 2005; 46: 12849.
  • 22
    Gernsbacher MA, Dawson M, Goldsmith HH. Three reasons not to believe in an autism epidemic. Curr Dir Psychol Sci 2005; 14: 5558.
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  • 23
    Wing L. The autistic spectrum. Lancet 1997; 350: 176166.
  • 24
    American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 4th edn. Washington DC : American Psychiatric Association, 1994.
  • 25
    Bishop DVM, Adams C. Conversational characteristics of children with semantic-pragmatic disorder II. What features lead to a judgement of inappropriacy? Br J Disord Commun 1989; 24: 24163.
  • 26
    Bishop DVM, Hartley J, Weir F. Why and when do some language impaired children seem talkative? J Autism Dev Disord 1994; 24: 17797.
  • 27
    Bishop DVM, Chan J, Adams C, Hartley J, Weir F. Evidence of disproportionate pragmatic difficulties in a subset of children wit specific language impairment. Dev Psychopathol 2000; 12: 17799.
  • 28
    McArthur GM, Bishop DVM. Which people with specific language impairment have auditory processing deficits? Cog Neuropsychol 2004; 21: 7994.
  • 29
    Norbury CF, Nash M, Bishop DVM, Baird G. Using parental checklists to identify diagnostic groups in children with communication impairment: a validation of the Children's Communication Checklist - 2. Int J Lang Commun Disord 2004 39: 34564.