Emotional disclosure has been suggested to alleviate psychological and physical stress in chronically ill people. Emotional engagement, cognitive restructuring, and positive future directedness are considered core elements to induce change in emotional disclosure interventions. The aim of our randomized controlled trial in patients with rheumatoid arthritis is to examine the psychological, clinical, and physiological effects of an emotional disclosure intervention adapted for home application and the modulating role of cognitive-emotional change and individual differences in emotion regulation.