Feasibility and acceptability of a self-guided, video-based brief ACT intervention: a pre-post observational study in a naturalistic setting

Objective This study examined the feasibility, acceptability, and preliminary efficacy of a brief, self-guided, video-based Acceptance and Commitment Therapy (ACT) intervention in a general population sample. Four domains were assessed: feasibility under naturalistic conditions, acceptability, preliminary efficacy (psychological flexibility, anxiety, depression, and self-compassion), and predictors of programme completion.Method A single-group, pre–post observational design was used. Adults (N = 219) registered online; 160 initiated the programme and 24 completed it. Feasibility outcomes included completion rate, comprehension of ACT metaphors, confidence in committed actions, and exercise completion; acceptability was measured through session-specific and overall satisfaction ratings.Results The completion rate was 11%, consistent with real-world unguided digital interventions. Acceptability, perceived usefulness, and engagement with experiential exercises were high. Among completers, psychological flexibility, self-compassion, and anxiety improved, whereas changes in depressive symptoms were minimal. Baseline characteristics largely did not predict adherence.Discussion A brief, video-based ACT intervention appears feasible and acceptable for self-selected users in real-world conditions, though overall engagement remained low. Improvements among completers should be interpreted cautiously given the small sample. Such interventions may serve as scalable tools within stepped-care mental health models and warrant controlled research to optimise design, confirm clinical effects, and enhance adherence.