Akihiko Masuda

Acceptance and commitment therapy (ACT) is a process-based, transdiagnostic approach to treatment that seeks to increase values-based, adaptive functioning (i.e., engaged living [EL]) in part through attenuating the impact of experiential avoidance (EA). The present case-series study examined EL and EA as mechanisms of change within a 10-week course of individual ACT delivered via a telehealth platform. Participants were two adult women with mental health concerns associated with clinically elevated EA. Throughout the study, we collected (a) daily self-monitored clinically relevant behaviors, (b) daily and weekly measures of EL and EA, and (c) pre-, mid-, post-treatment, and 3-month follow-up measures of psychopathology, quality of life, and ACT-related outcome variables. Results showed support for the efficacy of ACT, with both participants demonstrating slight improvements in clinically relevant behaviors, along with expected improvements in EL and EA. These favorable results were most pronounced for Participant 1. Results are discussed in the context of COVID-19-related adaptations (including telehealth), and within the framework of process-based ACT and its transdiagnostic applicability to a range of mental health concerns.