To many, keeping a diary is a personal, and often therapeutic, routine. While sitting down to journal may help people sort through emotional and psychological issues, researchers have now found that expressive writing can also help people recover more quickly from physical injuries.

In a study led by researchers in New Zealand, older adults who had undergone a biopsy were able to heal more quickly if they wrote about traumatic events and their emotions relating to those events, than other biopsy patients who simply wrote about daily activities. “This is the first study to show that writing about personally distressing events can speed wound healing in [an older] population that is at risk of poor healing,” said Elizabeth Broadbent, senior lecturer in health psychology at the University of Auckland in New Zealand, according to Time.

The study reviewed 49 overall healthy adults, ages 64 to 97, who were all assigned to write for 20 minutes per day for three consecutive days. Half of these patients were asked to “write about the most traumatic/upsetting experience in their life, delving into their deepest thoughts, feelings, and emotions about the event, ideally not previously shared with others,” while the other half were required to “write about their daily activities for tomorrow, without mentioning emotions, opinions, or beliefs.” Two weeks after writing, the researchers took small skin biopsies, which left wounds on all the participants’ arms. These wounds were photographed to mark the healing progress. Broadbent found that 76 percent of those who had written about difficult events in an expressive manner had fully healed 11 days after the biopsies, while 42 percent of the other group had. “We think writing about distressing events helped participants make sense of the events and reduce distress,” Broadbent told Scientific American.

While the results of the study show that there is some link between expressive writing and physical healing, the reasons behind the phenomenon seem unclear. Those who had written about traumatic events did not report any reduced levels of stress or depression, according to the authors, although the writing did appear to improve their sleep — which most likely played a role in the healing. A previous study done in 2005 came to a similar conclusion, noting that although writing appeared to help patients, it was uncertain what the underlying reasons were: “The mechanism of action appears to be complex, with the demonstrated benefits potentially resulting from some combination of immediate cognitive and/or emotional changes, longer-term cognitive and/or emotional changes, social processes, and biological effects, rather than being accounted for by any single factor,” the authors write.

Likewise, every patient is different, and finds unique coping mechanisms for emotional problems. While writing may improve the overall mental health of some patients, others might find that reliving difficult experiences through writing could trigger post-traumatic stress disorder (PTSD) symptoms. For others, sorting through emotions that are often too sensitive to be discussed face-to-face may be therapeutic if done on paper.

The authors of the recent New Zealand study note in their Conclusion that further research will need to be completed to analyze the “underlying cognitive, psychosocial, and biological mechanisms contributing to improved wound healing from these simple, yet effective, writing exercises."

Source: Broadbent E, Koschwanez H, Kerse N, et al. Expressive Writing and Wound Healing in Older Adults: A Randomized Controlled Trial. Psychosomatic Medicine. 2013.