TUESDAY, Jan. 29 (HealthDay News) -- Some doctors may really "feel" a patient's pain -- and also experience relief after they've given the patient treatment, new research suggests.

In the new study, scientists scanned the brains of doctors as they believed they were offering patients pain-relieving therapy.

The more empathetic the doctor, the more brain activation the researchers found.

"It's the doctor side of the placebo effect," said researcher Ted Kaptchuk, director of the Program in Placebo Studies and Therapeutic Encounter at Beth Israel Deaconess Medical Center and Harvard Medical School in Boston.

"Not only do doctors mirror their patient's own pain, but when doctors are relieving the pain of their patient, they will also activate their own expectations of pain relief regions of their brain," added study co-author Karin Jensen, an investigator at Massachusetts General Hospital's Martinos Center for Biological Imaging. She also works with Kaptchuk in the placebo studies program.

Eighteen doctors from nine medical specialties participated in the study. The "patients" were two 25-year-old women who -- unknown to the doctors -- were only pretending to have pain that needed treatment.

To add to the illusion, the researchers first gave the doctors a mild dose of "heat pain" administered to their forearms, and then showed them how the device they were using on the patients could ease their discomfort.

Next, the doctors met with the patients to conduct a typical 20-minute exam. The researchers said this was aimed at building a rapport between physician and patient.

The patients were then seated next to the scanner, where doctors could see them through a mirror. Following instructions, the doctor used a remote control to push a button they thought would activate the device and relieve the patient's pain or to push a button they thought provided no relief.

The sham patients, on cue, grimaced when the pain-relieving button was not pushed and looked relaxed or neutral when it was pushed.

Real-time MRIs were used to track the doctors' own brain responses. When the doctors saw that the patients were in pain, there was more activation in a region that commonly becomes more active when feeling one's own pain or that of others, Jensen said. The region is known to be associated with empathy.

Conversely, when the doctors thought they were effectively "treating" the patient, the region of the brain known to be involved in the placebo response was activated.

Doctors who had scored high previously on their ability to view things from the patients' perspectives also were more likely to show activation in a region linked with reward, which is closely linked to the placebo-response area, Jensen said.

"Doctors activate their own brain regions for expectation of pain relief when they treat patients in pain," she concluded.

Whether the activation in the brain regions of the doctors is greater than that of a patient who is actually feeling the pain is not known from this study, Jensen said, but she hopes to study that in the future.

After the experiments, the doctors were told the patients were not real and offered a chance to withdraw. None did.

Although the study is a "good line of research," some of the findings might be explained simply by the basics of social interaction, noted Issidoros Sarinopoulos, assistant professor of radiology at Michigan State University. Sarinopoulos has also researched the topic.

"The doctor is expecting to see positive results," he pointed out, and "that may be why that part of the brain is activated."

Jensen agreed that social interaction could possibly intensify the effect, but would not explain it entirely.

Would the results play out in real life, when your doctor may not have ever had the condition you are complaining of? According to Jensen, previous research seems to suggest that it is the doctor's ability to understand a patient's perspective that matters more, rather than his or her having a prior personal history of the condition.

The research does suggest that "you should look for doctors who do care," Sarinopoulos said.

To Kaptchuk, the bottom line is this: "A caring doctor is not just something you feel, but there is real biology here."

More information

There's more on the placebo effect at the U.S. National Center for Complementary and A...rnative Medicine.