There are some really cool benefits to expressive writing, It has physical and emotional benefits. Dr. James Pennebaker spent a large portion of his career studying the benefits.
James W. Pennebaker is Professor Emeritus of Psychology. He is continuing to explore natural language use, group dynamics, and personality in both laboratory and real world settings. His earlier work on expressive writing found that physical health and work performance can improve by simple writing and/or talking exercises. Author or editor of 12 books and over 300 articles, Pennebaker has received numerous research and teaching awards and honors. Books include:
"Expressive Writing: Words That Heal"
"Opening Up by Writing It Down: How Expressive Writing Improves Health and Eases Emotional Pain"