My last point concerns Dr. Happé's citing the study by Lord and colleagues
5 of which Dr. Happé writes: "the same studies suggest that clinicians show good agreement about who falls within versus outside the autism spectrum". The citation does echo the first part of the rationale for the DSM-5
6 changes to the criteria for autistic disorders that were put on line for comment by the APA. It read: "Differentiation of autism spectrum disorder from typical development and other "nonspectrum" disorders is done reliably and with validity". I don't know the basis for this. If it is meant that some tool for diagnosing these disorders such as a structured interview or rating scale has such sensitivity, specificity and precision, I don't think that this has been shown. My criteria for Asperger's Disorder derives from my interpretation of the DSMs in the light of the mass of literature, including scholarly articles and first hand accounts of individuals so diagnosed, that have accrued over the years since 1994 and attest to the value of having placed Asperger's Disorder in the DSM-IV, flawed criteria or not.
References
1Happé M. Editorial: Criteria, Categories, and Continua: Autism and Related Disorders in DSM-5. J Am Acad Child Adolesc Psychiatry. 2011;50:540-542.
2Mattila ML, Kielman M, Linna SL et al. Autism spectrum disorders according to DSM-IV criteria; an epidemiological study. J Am Acad Child Adolesc Psychiatry. 2011;50:583-592.
3Williams K et al. Diagnostic labeling of autistic spectrum disorders in NSW. J. Paediatr Child Health, 2008; 44:108-113.
4American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 3rd., 3rd. revised and 4th. editions respectively. Washington, DC: American Psychiatric Association, 1980, 1987 and 1994.
5Lord C, Petkova E. Hus V et al. A multi-site study of the clinical diagnosis of different autism spectrum disorders. Unpublished manuscript, 2011. {This paper was published in the Archives of General Psychiatry, 2012; 69: 306-313 after I submitted my letter.}
6American Psychiatric Association. Proposed draft revisions to DSM disorders and criteria.
www.dsm5.org/proposedrevisions.