UF Researchers Explore Why Patients’ Pain Recall May Be More Than Total

March 31, 2004

GAINESVILLE, Fla. — In a perfect world, a visit to the dentist’s office would be stress-free and painless. But if you’re like 25 million other Americans, the mere thought of reclining in a dentist’s chair probably fills your heart with dread.

You may have been there before and it didn’t feel good. Or, at least, you think it didn’t.

Now, a report published by University of Florida College of Dentistry researchers in this month’s Journal of Pain demonstrates much of that negative recall may be mostly in your head. It turns out that an individual’s memory of pain intensity months later may have more to do with how emotionally stressed the person was during the experience than with how painful the experience actually may have been.

“Clearly, many dental and medical procedures are aversive and anxiety-provoking, fear-provoking and uncomfortable in general,” said Jeffrey J. Gedney, a pain behavior research fellow in the college’s division of public health services and research. “What we found was that emotional factors became a better predictor over time of what people would recall than was their level of pain during their experience.”

The study was designed to measure just how much stress — such as the normal anxiety one may feel when receiving medical treatment — influences how painful people remember their experience being. Researchers found that subjects who were stressed during their painful experience recalled more pain after several months than they reported at the time of the painful event, and women remembered more pain than men.

Study subjects, 52 men and 48 women, were asked to complete two 15-minute experimental sessions, one stressful and one stress-free. In the stress-inducing session, they were asked to give extemporaneous speeches about difficult social issues to a live audience and before a video camera. During the non-stressful session, participants were allowed to read neutral magazines about gardening or travel. Stress levels of people in both sessions were measured by before and after questionnaires, sampling for stress hormones in saliva and monitoring heart rate. Subjects were found to have both emotional and physical stress responses to session activities during only the stress session.

After both sessions, participants were asked to complete a two-minute pain task in which they rated the severity of their pain from an “ice-cream headache” caused by holding a bag of crushed ice against their foreheads. Subjects then completed another series of questionnaires designed to rate their emotional states immediately after the pain task.

To determine how much and what subjects remembered of their pain over time, researchers conducted telephone interviews of 68 people who agreed to participate in a six-month follow-up survey.

“We found that nearly everyone recalled more pain at six months than they reported at the time of the experience,” said Henrietta L. Logan, director of the college’s division of public health services and research and Gedney’s co-investigator. “Women tended to recall more pain, and moreover, people in the stress condition recalled more than people from the non-stress condition.”

Patients recalled nearly 10 percent more pain from the stress session than from the non-stress session. Additionally, the emotional state of the subject during the follow-up interview also seemed to influence the level of pain they recalled, Logan said.

“So, what we propose is that emotions, indeed, do have an influence on how people process and recall, at least in this case, painful experience,” Gedney said, although he was careful to clarify that more research is needed to understand the gender differences in pain recall.

“The findings of this report indicate that health-care providers have added reasons to be careful to recognize and treat not just the clinical symptoms of disease, but the emotional reactions of patients during treatment,” said Robert Baron, a professor of psychology at the University of Iowa. “Failure to do so will often heighten the patients’ negative recollection of treatment stress, which in turn will be likely to discourage them from seeking follow-up or continued treatment.”

Logan said health-care providers and their staff have a responsibility to recognize and address this phenomenon in patients.

“If the goal of the caregiver is to make the patient’s experience as positive as possible, and to reduce anxiety by establishing a pleasant setting and paying particular attention to the personal comfort of the individual, it’s bound to make a difference not only in the patient’s willingness to come back but also in their long-term recall of the amount of pain they experienced,” Logan said.