Objectives. To examine whether a novel workplace intervention designed to increase worker voice can reduce psychological distress and improve emotional vitality at 6- and 12-month follow-up. Methods. We conducted a cluster-randomized controlled trial in 16 fulfillment centers throughout the United States between 2021 and 2023. Data were collected at 3 time points; 2813 workers participated in at least 1 survey. Treated fulfillment centers established a new, participatory committee called the Health and Well-Being Committee. We compared differences in psychological distress and emotional vitality and explored differential treatment effects by gender. Results. At baseline, 51% of the participants reported moderate or severe psychological distress. Intervention sites had lower average psychological distress at the 6-month follow-up compared with control sites, with no significant differences at 12-month follow-up. Gender moderation analyses suggest the Health and Well-Being Committee was particularly effective in reducing psychological distress among men at 6-month follow-up. Conclusions. Our findings suggest that opportunities for workers to share concerns with a committee of their peers tasked with identifying solutions can support mental health. Our study contributes important experimental evidence on workplace interventions that improve the well-being of low-wage US populations. Trial Registration. Clinicaltrials.gov identifier: NCT05199415. (Am J Public Health. Published online ahead of print January 15, 2026:e1-e11. https://doi.org/10.2105/AJPH.2025.308352).
Siebach et al. (Thu,) studied this question.