I regularly tout the benefits of writing and of practicing writing (or at least it has been a common theme in my writing over years, if not in recent blog posts). A recent study at Michigan State University associated specific benefits associated with expressive writing—writing about feelings and thoughts. (https://www.eurekalert.org/pub_releases/2017-09/msu-fwe091417.php)
The authors of the study compared two groups of students who were set to perform the same main task—a test, and also a secondary task, either writing about what they did the previous day (not expressive) or writing about their feelings about the upcoming test (expressive). Their basic finding was that those doing the expressive writing were calmer (actually, they described it in terms of brain activation states because they were measuring the students with electroencephalography). The lead author used a automotive fuel-efficiency metaphor, saying the difference between the brains performing the expressive writing task and those performing the control (non-expressive) task was like the difference between a Prius and a gas guzzler from the 1970s. The students in the two groups performed the same on the main task (the test), so there was no direct impact on performance on the test itself. I am unsure from what I have read whether the higher-efficiency brain activity induced by the expressive writing task lasted into the main task. In any event, this is good evidence that there is a real benefit to writing about your own feelings about a task.
For people who are stuck, I have often recommended writing about their feelings about the project—which has sometimes worked. One reason I like having people write about ow they feel about a project is that it can help reveal crucial theoretical assumptions. Another reason is that once someone has started writing about their feelings about the project, that can often transition into writing about the project itself. This study suggests that writing about how you feel about a project can help calm you down.
The many who have suggested that writing has therapeutic benefit—and there are many such in the self-help shelves—seem to have evidence to back up at least some claim to therapeutic benefit.
Generally speaking, writing is an important practice for people who will need to express ideas in their lives—both professionals and academics. No matter how difficult writing may seem, it gets easier when you practice, and that allows you to work more efficiently because you communicate with others more efficiently. This recent study suggests yet another reason to practice writing—or at least expressive writing: it helps improve your mental state.