In The Politics of Autism, I discuss evaluation and diagnosis .
In any policy area, the act of gathering data brings out cases. Counting may legitimize discussion of uncomfortable topics. It enables people with a condition to come forward as a group instead of solitary individuals. Official record-keeping opens a channel for reporting: once an organization announces that it is keeping count, people send it information. Such reactive effects are especially strong when benefits attach to membership in a category.John Elder Robison at Psychology Today:
When psychologists complain that today’s autism spectrum is too broad, one point is seldom mentioned: If not autistic, how would they describe a person who qualifies for an autism diagnosis under DSM5, but would not qualify under DSM III? I am an example, and I can tell you from experience that the diagnostic labels I received prior to being diagnosed autistic were far less useful.
While psychologists might benefit from a smaller more defined spectrum, people like me most assuredly did not benefit from that arrangement. Understanding I am autistic gave me a framework for changing my life. Understanding that I had trouble engaging other people told me nothing beyond what I could see for myself. Other labels I received before my autism diagnosis were useless or even harmful.
Some may argue that lumping bright people and intellectually disabled people into one autism spectrum marginalizes the intellectually disabled people. While I do think bright autistic people shape popular public opinion in ways that are not always realistic, I do not think our presence in the autism community deprives cognitively disabled people of services.
The sad truth is, people with severe cognitive disability have always been hidden from sight, and their treatment has often been poor. Conditions for intellectually disabled people are better overall than they were a generation ago.
Diagnostic labels tend to follow the money. If there is more funding for intellectual disability more people will be diagnosed with ID. The need for services for intellectually disabled people is obvious. The recognition that bright quirky disabled people need help too does not take away from that.