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If you've just been through a breakup, you might want to think twice about writing your feelings down—at least according to some surprising new findings.

In a study at the University of Arizona, 90 people who had recently separated or divorced were put into three groups: In one, people wrote about the emotions they were going through.

The second group used "narrative expressive writing," which entails putting feelings in the framework of a story with a beginning, middle, and end. Those in the control group just kept a journal of their daily activities, without any emotions or opinions at all. All the volunteers were asked to write for 20 minutes a day for three consecutive days.

After a follow-up session eight months later, researchers were surprised to find that it was the people in the two test groups—-those who had participated in the expressive writing—-who reported more emotional distress than those in the control group.

This effect was found among those participants labeled "high ruminators"—people who have a tendency to dwell on their negative experiences. The high-ruminators in the control group were found to have the least amount of unhappiness during the follow-up, indicating that, for high ruminators, anyway, putting difficult emotions in writing may make recovery more difficult.

"I think many, many therapists have a tendency to believe that journaling unequivocally is a good thing to do, especially when people are trying to figure things out in their head," lead author David Sbarra, a psychological scientist at the University of Arizona, told ScienceDaily. "This study is important because it challenges our notions about what might be the thing to do to promote healing after a divorce," he said. "It makes us reconsider the things we do to try to put our lives back together."

The study is to be published in Clinical Psychological Science, a journal of the Association for Psychological Science.