Expressive Writing
Expressive writing is James Pennebaker's paradigm: write continuously about an upsetting or traumatic experience for fifteen to twenty minutes a day, on three or four consecutive days, without worrying about grammar or about whether anybody will read it. It is the most studied writing intervention in psychology. The effect is real, and it is small, and it got smaller as the reviews got bigger and better. The first synthesis, with fourteen trials, reported a moderate benefit. The review with a hundred and forty-six randomised trials found one roughly a third that size.
What it is
The paradigm is not journalling, and it is not the same as putting one word on a live feeling. It is a fixed protocol with a fixed dose, tested in randomised trials against a control group who write about something neutral, such as how they spent yesterday.
A typical participant writes for twenty minutes on four evenings about something they have never told anyone. They feel worse on those evenings. Months later, on average and across many trials, people in that condition report slightly better health and mood than the people who wrote about the neutral topic. Both halves are part of the finding, and the unpleasant half is the one that gets left out.