Acceptance and Commitment Therapy: radici, modello, evidenze.

Acceptance and Commitment Therapy (ACT; Hayes, Strosahl and Wilson, 1999) is a behavioural model, clearly based on both epistemological and theoretical roots, which we must be aware of in order to clarify its breadth and depth and to prevent misunderstandings and simplifications. For this reason, the opening paragraphs will be dedicated to briefly setting the model within the philosophical framework of functional contextualism and rooting it theoretically in the functional analysis of behaviour and Relational Frame Theory (RFT; Hayes, Barnes-Holmes and Roche, 2001). Next, the six processes of the ACT model and the empirical evidence so far produced will be presented. Given the large amount of scientific literature about the ACT model as a whole, its components and processes, and its theoretical basis, the evidence will be illustrated in sub-paragraphs: evidence on ACT as a unitary intervention, its strengths and weaknesses based on the comparison of ACT with other forms of cognitive behavioural therapies, duration of ACT outcomes, consistency between outcomes and hypothesized processes of change, evidence on ACT as a transdiagnostic intervention, evidence on the correspondence between the processes assumed in the model and the basic theory, and RFT.