This article examines the adoption in Québec of the evidence-based practice, Integrated Psychological Treatment (IPT) of people with schizophrenia and the longevity of this practice within nine clinical milieus in a context of transformation of services. A team of researchers of the Centre de recherche Fernand Seguin has closely followed the implementation and the maintenance of the IPT in nine clinical milieus. More specifically, this article presents the factors that have contributed, on a five year period, to the maintenance (or not) of the IPT in these settings. It raises the important question of longevity of an approach that is specialized and specific to a clientele in contexts of transformation of services.