But new evidence suggests "getting it off your chest" may not be the right thing to do.
Psychologists in the US used an online survey to test people's responses to the September 11 2001 terrorist attacks on New York and Washington.
Those who chose to express their thoughts and feelings were compared with those who did not over a two-year period.
To their surprise, individuals who bottled up their feelings ended up better off.
They suffered fewer negative mental and physical health symptoms than people who were willing to talk.
The results have important implications for expectations about how people should react to collective trauma that affects a whole community or nation, said the researchers.
It also called into question the pleas made to people caught up in shocking events to come forward and "open up".