[3][5] In September of that year, they joined the Institute for Medical Humanities at Durham University as an assistant professor of Critical Neurodiversity Studies.
Chapman argues that the correct interpretation of the concept of neurodiversity contributes to the further development of its theoretical and practical side, and that its multiple definitions are evolving over time.
[12] Much of their work has been on the fundamental concepts of neurodiversity as they pertain to philosophy of science, most notably their development of an ecological model of mental functioning[13] and analysis of the metaphysics of diagnosis.
[14] Gerald Roche has argued that Chapman's definition of neurodivergent Marxism is “an intersectional approach to analysing how capitalism produces and maintains multiple forms of oppression, to ensure that new sites of extraction can be constantly identified and exploited in the endless pursuit of capital accumulation.”[15] Awais Aftab has said that Chapman's work “has had a substantial impact on my own thinking, and their writings have consistently forced me, and many others, to rethink long-standing assumptions related to pathology and medical care.”[11] Julie Dind stated in a review of the book Neurodiversity Studies: A New Critical Paradigm, which included Chapman's writings, that one of their essays successfully challenges the tragic perspective on autism promoted by medicine.
[17] In various articles and especially in their book Empire of Normality: Neurodiversity and Capitalism, Chapman has criticized how psychiatrists and the field of psychiatry deal with the issue of mental health and disability.
In this book, they build on existing work that urges the need for alternatives to psychiatry and clinical psychology, led by and for neurodivergent people alongside those who identify as mad, psychiatric survivors, and disabled.
John Cromby, for Mad in the UK, responded critically to Chapman's approach in Empire of Normality, arguing that the work “misrepresents antipsychiatry” in terms of historical context and use of the term, and argued that it “tends towards idealism.”[19] Sam Fellowes for Philosophy of Medicine described Chapman's discussion of anti-psychiatry as “nuanced and helpful”, providing a balanced view of anti-psychiatry which distinguishes between different ideologies in the tradition, and acknowledges that even those the author opposes raised important issues.