According to James Pennebaker, writing about our feelings and emotions or about what's upsetting us, can help not only mental health but also pshysical health.
Prof. James Pennebaker, from the University of Texas, has been conducting experiments for decades and found that writing 15 min a day for, say, 4 days in a row, can be truly helpful.
I have been listening to his interview to BBC 4 and was specially struck to the benefits in general health felt by women with breast cancer who followed Pennebaker's instructions.
The procedure is quite simple. I'll quote from Prof. Pennebaker's site:
Promise yourself that you will write for a minimum of 15 minutes a day for at least 3 or 4 consecutive days.
Once you begin writing, write continuously. Don’t worry about spelling or grammar. If you run out of things to write about, just repeat what you have already written.
You can write longhand or you can type on a computer. If you are unable to write, you can also talk into a tape recorder.
You can write about the same thing on all 3-4 days of writing or you can write about something different each day. It is entirely up to you.
What to Write About
Something that you are thinking or worrying about too much
Something that you are dreaming about
Something that you feel is affecting your life in an unhealthy way
Something that you have been avoiding for days, weeks, or years.