[1][2] Donald Triplett, the first person diagnosed with autism, and[3][4][5] psychiatrist Leo Kanner are also covered, as is the ongoing[6] debate concerning the neurodiversity movement, especially with respect to autistic people with more apparent support needs.

The authors discuss the importance of redefining the disorder so that more people with autism can receive treatment and improve their quality of life.

[7] Kirkus Reviews wrote that the book was compelling and well-researched, and the authors blended the search for treatment with the personal stories of various individuals.

[8] Spectrum wrote that the book provided a meticulous, absorbing stepwise chronology of how the perception of autism changed from being unknown to being abhorred, then later accepted.

[10] In a Different Key was a finalist for the 2017 Pulitzer Prize for General Nonfiction, described by the reviewers as "a passionate work of advocacy that traces public perceptions about autism from chillingly cruel beginnings to a kinder but still troubling present.