This article reports on a Danish study on interprofessional collaboration between child psychiatrists and educational psychologists concerning children who are categorised as being at risk. Methodologically, the analysis is grounded in qualitative interviews with psychologists. A Foucauldian approach is applied to narratives and experiences that occur within these interviews concerning external collaboration with child psychiatrists. The article is informed by the research tradition that has problematised the significance of psychiatry and diagnoses in the field of special needs education and social pedagogy. We thus enquire into how the rise of diagnostics and medicalisation affects our understanding of children's difficulties. We discuss a paradox that is present in Denmark and other countries. As educational policies emphasise inclusion, the field of schooling experiences a huge rise in children with medical diagnoses. We argue that diagnostic knowledge is itself an insufficient basis for action and must be considered in relation to teachers' overall training and teachers' situated professionalism.