Abstract: Assimilation model is a theoretical model concerning the change process of psychotherapy. It incorporates the ideas from different theorists, establishing an integrated framework to explain the general change process of psychotherapy. According to the assimilation model, the change process of psychotherapy undergoes eight predictable stages. The presence of the eight stages and their developmental process has been empirically supported by a series of studies. The existing findings also show the differences in the patterns of assimilation process among different therapists and in the effect of different type of therapy on the clients at differing assimilation stages. In addition, prior researchers have made attempt to refine their studies by expanding their interest to the specific markers and substages of the assimilation process, to different mental disorders, and treatments, and to some other new research fields (e.g. pharmacotherapy, loss in immigration). Future studies may focus on a) cross-cultural examination on the cultural adaptability of the model; b) the examination of the potential hypothesis of the model on the linear process of change, and c) the voices.

Key words: assimilation model, problematic experiences, problematic voices, dominant voices, meaning bridge