By Andrew M. Seaman
NEW YORK (Reuters Health) - If a person doesn't have much success with one pain treatment, they may say the next one they try doesn't work so great either, suggests a new study from Germany.
Previous studies have found that people receiving a dummy pill in clinical trials don't fare as well once they're switched to the real drug, compared to those who have been getting the real treatment all along, according to Dr. Ulrike Bingel, the study's lead author from the University Medical Center Hamburg-Eppendorf.
The phenomenon has also been looked at before in people trying the same treatment twice, but she said doctors typically move on to other treatments if the first one doesn't work.
For the study, published in a research letter in JAMA Internal Medicine, the researchers recruited 39 healthy people to undergo three days of testing.
Each person was outfitted with patches that heated up on their arms to create a moderate amount of pain on the first two days.
One group had an inactive cream applied to their patches, and researchers lowered the pain level to make them think the cream was working. The other group had the same cream applied to their patches but the pain level was kept the same to make them think it wasn't working.
The experiment was repeated on the third day but both groups were told that they were receiving a different treatment, and the researchers lowered the pain level in each group.
On a scale from 0 to 100 - with a higher score signifying more pain - the researchers lowered the pain of each group from 80 to 50 after applying the cream.
The group that had the successful "treatment" the day before reported their pain levels dropped from 81 to 40. The group that had a negative "treatment" the day before reported their levels dropped from 81 to 54.
Bingel told Reuters Health that the 14 point difference between the two groups would be noticeable to the average person.
What's more, images of each person's brain showed the group that had the previous negative experience felt more pain.
"This was not the patient saying, ‘Well this didn't work, I'll just tell them it's not working.' We saw their brains telling them they had different levels of pain," said Ted Kaptchuk, an expert on placebo effects at Beth Israel Deaconess Medical Center in Boston.
But Kaptchuk, who was not involved with the new research, said it's hard to make any firm conclusions from a small trial.
"What it does suggest is that doctors need to know about people's previous experiences with medications," he said.
SOURCE: http://bit.ly/15gth9d JAMA Internal Medicine, online June 17, 2013.