Abstract
Despite much research on the beneficial effects of written disclosure, relatively little attention has been paid to specifying the mechanism underlying the effects. Building upon the two theoretical models (the cognitive adaptation model and the emotional exposure-habituation model), this research focused on two aspects of disclosure content-insights and emotions-and examined how women with breast cancer benefit from written disclosure in online support groups. Using survey data collected at baseline and after four months and messages posted in bulletin-board-type online groups in between, we analyzed how the content of disclosive messages predicted health outcomes. Disclosure of insights led to greater improvements in health self-efficacy, emotional well-being, and functional well-being, which was mediated by lowered breast cancer concerns. Disclosure of negative emotions did not have main effects on health outcomes; instead, it weakened the unfavorable association between concerns at baseline and functional well-being at follow-up. Our findings support both theoretical models, but in regard to different aspects of disclosure content.