Has the Doubter put in an appearance yet, claiming that Undoing the past can’t possibly relieve asthma symptoms? Has he insisted that you be logical, use good common sense, and look at this from a scientific point of view? Wonderful! According to a recent study on the effects that writing about stressful experiences has on the symptoms of asthma, he hasn’t a leg to stand on. This study used writing instead of imagery, yet the results are similar — including the statistics. 
Researchers asked patients to draw on their inner beliefs, thoughts, and feelings about a past event and to experience them within a creative context. According to this controlled clinical trial, thirty-nine asthma patients completed an experiment in which they wrote about the most stressful event of their lives. They did this for twenty minutes on three consecutive days a week for one week and were evaluated at two weeks, two months, and four months after treatment. Starting at two weeks, 47 percent of the patients who were treated showed clinically relevant changes in lung function, as compared with changes of 24 percent in the control group.
This rigorous study, conducted at the State University of New York, Stony Brook, School of Medicine by Dr. Joshua M. Smyth, is the first to prove that writing about stressful life experiences improves physician ratings of disease severity and objective physiological markers. While participating patients wrote about their most stressful experience, control group patients wrote about their daily activities. All were asked to write continuously, without regard for spelling, style, or other artistic or editorial concerns, and were signaled to stop after twenty minutes. They could write about one topic for three sessions or could move from one topic to another. None of the work was discussed with staff or with other participants in the study. Most often, they wrote about deaths of loved ones, serious relationship problems, disturbing events of childhood, or occasionally of seeing or being involved in a major disaster.
Those who decide to use this technique must be willing to go the course: this means to write for the full twenty minutes, for three days, about something that matters, something really distressing, not just the events of the day. As Dr. Smyth observed, and as the Awfulizer will surely point out, this can be painful. Yet its value is enormous. By writing about the stress or trauma, you bring to the surface emotions and memories that may have been stuck inside you for years, and you expel them. This of itself is a kind of exorcism.