“…ACT is a transdiagnostic, process-based, contextual behavioral therapy. It is philosophically and theoretically rooted in functional contextualism ( Hayes, 1993 ) and relational frame theory (RFT; Hayes et al, 2001), respectively. The ACT model suggests that psychological inflexibility is at the core of psychopathology and consists of a functional class of behavior in which ongoing private experiences dominate responding over chosen values ( Bond et al, 2011 ; Luciano et al, 2022 ; Törneke et al, 2016 ).…”