A Multiple‑Baseline Evaluation of Acceptance and Commitment Therapy Focused on Repetitive Negative Thinking for Comorbid Generalized Anxiety Disorder and Depression

Delayed multiple baseline study with six adults with GAD-depression comorbidity. A 3-session individual ACT protocol focused on RNT was applied. Five of six participants showed clinically significant changes in symptoms and RNT; very large effect sizes on emotional symptoms, pathological worry, experiential avoidance, and cognitive fusion. Preliminary results support the efficacy of brief RNT-focused protocols.