Putting pen to paper is said to help the brain "regulate emotion" and reduces feelings of anxiety, fear and sadness.
Researchers claim the act of writing about personal experiences has a cathartic effect because it inhibits parts of the brain linked to emotional turmoil, and increases activity in the region to do with self-control.
The quality of the verse or prose written has no bearing on the effect on the author. In fact, scientists suggest that the less vivid and descriptive the piece, the better.
Now they hope to develop therapies based on their findings that could be used to ease social fears and phobias.
Dr Matthew Lieberman, a neuroscientist at the University of California, outlined his findings at the American Association for the Advancement of Science in a lecture called Putting Feelings Into Words.
He said that expressing yourself in print was "a sort of unintentional emotion regulation".
"It seems to regulate our distress," he added. "I don't think that people sit down in order to regulate their emotions but there is a benefit.
"I think it could play a role in why many people write diaries or write bad lyrics to songs - the kind that should never be played on the radio."
Dr Lieberman proved the therapeutic power of writing by scanning the brains of 30 individuals while they described distressing pictures.
He found that the act tended to reduce activity in the amygala, a part of the brain connected with emotion and fear and increased activity in the pre-frontal cortex, the mind's regulator.
This suggests that the mere action of writing about an emotion was a way of calming down the brain and re-establishing mental balance.
Often the author is unaware of the therapeutic effect of the task, it was claimed.
"If you ask people then they don't think that it serves an emotion regulation but when you look at the brain that looks like what is going on," he added.
"The more frontal activity we see, the less amydala response. There seems to be a see-saw affect."
In another trial, writing was used in conjunction with exposure therapy for people who had a phobia of spiders.
It was discovered that writing about their fears actually boosted the effect of the therapy compared with people who did not put pen to paper.
"We do think that it has clinical applications," Dr Lieberman said.
"People expressing negative emotional responses in words while being exposed gave them greater attenuation (reduction) of fear."
Dr Lieberman said that the effect was negated if the writing was too vivid or descriptive because it led to people reliving their trauma. Also, typing was not as good as writing long-hand.
"You have to write about it in a detached way," he said.
Asked why writers were often troubled souls, he said that the writing itself may be a reaction to severe emotional problems.
"I am sure that it is one of their motivators to write," he said. "You have to ask yourself what they would be like without the writing."
Source: http://www.telegraph.co.uk/culture/culturenews/4630043/AAAS-Writing-poems-helps-brain-cope-with-emotional-turmoil-say-scientists.html