Written emotional expression: effect sizes, outcome types, and moderating variables.

A research synthesis was conducted to examine the relationship between a written emotional expression task and subsequent health. This writing task was found to lead to significantly improved health outcomes in healthy participants. Health was enhanced in 4 outcome types--reported physical health, psychological well-being, physiological functioning, and general functioning--but health behaviors were not influenced. Writing also increased immediate (pre- to postwriting) distress, which was unrelated to health outcomes. The relation between written emotional expression and health was moderated by a number of variables, including the use of college students as participants, gender, duration of the manipulation, publication status of the study, and specific writing content instructions.