This paper examines the professional relationship and mutual influence of Winnicott and Dockar-Drysdale, particularly in relation to the development of the therapeutic principles underlying the treatment philosophy of the Mulberry Bush School. The first half of the paper considers evolving notions of therapeutic need and the provision of opportunities of regressive experience for unintegrated children in a residential setting. The second half considers the implications of this provision in the thinking of both, in terms of the organizational structure, staff consultation and demands of and on the support network.