Aesthetic experience as a candidate process linking group art therapy to social anxiety relief: a randomized trial with repeated process assessment

Background Direct verbal disclosure may be evaluatively demanding for university students with social anxiety. Group art therapy (GAT) offers an externally focused, materially mediated mode of engagement, but its active processes remain uncertain. Methods In an assessor-blinded, two-arm randomized trial, 120 students with elevated social anxiety were assigned to eight weekly sessions of GAT or a structurally matched supportive discussion group (SDG). Clinical outcomes were assessed at baseline, post-intervention, and 3-month follow-up; an adapted AEQ-derived session score and two study-specific cognitive process measures were assessed after each session and analyzed exploratorily. Results GAT produced larger LSAS-SR reductions at post-intervention (adjusted difference = −9.5, 95% CI [−15.3, −3.7], d = 0.63) and follow-up (−10.9, 95% CI [−16.7, −5.1], d = 0.71). Relative reductions calculated from group means were 35.6% and 41.4% in GAT, compared with 19.6% and 23.6% in SDG. The Condition × Session coefficient for the adapted AEQ-derived score was 0.27 ( p < 0.001), and exploratory indirect associations were observed through self-focused attention (−0.088) and negative self-evaluation (−0.061). Conclusion GAT was associated with greater and sustained improvement in social anxiety, while the repeated process findings support aesthetic engagement as a candidate process for further testing rather than an established causal mechanism.