"If talking about the past reduces ruminations and worries, how does it work? One idea is that translating experiences into words forces some kind of structure to the experiences themselves. Through language individuals are able to organize, structure, and ultimately assimilate both their emotional experiences and the events that may have provoked the emotions...Stiles proposes that talking about an event accomplishes two important goals. First, talking both reflects and reduces anxiety. Second, repeated disclosure over time gradually promotes the assimilation of the upsetting event."
Emotion, Disclosure and Health