Background <p>Anxiety disorders are highly prevalent worldwide and have significant comorbidities including depression and substance use disorders. The global burden of anxiety disorders necessitates early intervention for high-risk populations, including college students facing stress during major life transitions. Objective measures and ecological momentary assessments may advance the development of early interventions.</p> Objective <p>To test the efficacy of group cognitive-behavioral therapy (GCBT) intervention by implementing a randomized controlled trial and identifying potential objective measures.</p> Methods <p>College students with a Generalized Anxiety Disorder Scale 7 scores ≥ 5 were randomized into GCBT (<i>n</i> = 31) and wait-list control (WLC; <i>n</i> = 28) groups. For both groups, self-reported symptom severity was assessed at baseline and follow-up in weeks 4, 8, and 28. Continuous heart rate and step counts measurements were captured by wearable sensors, along with ecological momentary assessments of mood and energy, which were obtained within 4 weeks of treatment.</p> Results <p>Compared to the WLC group, the GCBT group showed significant improvements in anxiety symptoms at week 28. Moreover, the GCBT group had significantly increased step counts and faster heart rates, more stable moods in the morning and evening, and better energy in the morning. Improvements in anxiety symptoms were closely associated with increases in step counts in the GCBT group.</p> Conclusion <p>Preliminary findings suggest that GCBT is associated with improvements in anxiety symptoms in college students over the long term. Changes in daily heart rates and step counts were correlated with mood and energy levels, suggesting that physiological markers may be useful in assessing treatment response.</p> Trial registration <p>ClinicalTrials.gov (NCT05913349), trial registration date: June 13, 2023 (retrospectively registered).</p>