| Patients who believe in the effectiveness of | | | | asked to rate the intensity of their pain on |
| their pain medication will experience greater | | | | a scale of 0 to 100. After each scan, the |
| pain relief, finds a University of Michigan | | | | researchers asked the participants more |
| study published in the Journal of | | | | questions about their mood, emotions and |
| Neuroscience. Just thinking that a medicine | | | | other aspects of how they felt during the |
| will relieve pain is enough to prompt the | | | | scans. |
| brain to release its own natural painkillers, | | | | |
| results indicate. | | | | There were significant differences between |
| | | | ratings given by participants after the scan |
| The study, funded by the National Institutes | | | | in which they received the placebo compared |
| of Health, provides the first concrete | | | | to the scan during which they received the |
| evidence that endorphins, the brain's own | | | | jaw injection alone. |
| pain-fighting chemicals, play a direct role | | | | |
| in the phenomenon known as the "placebo | | | | "We were able to see that the endorphin |
| effect." | | | | system was activated in pain-related areas of |
| | | | the brain and that activity increased when |
| Endorphins behave similarly to opiate drugs, | | | | someone was told they were receiving a |
| such as heroin and morphine. They bind to | | | | medicine to ease their pain. They then |
| receptors and stop the transmission of pain | | | | reported feeling less pain. The mind-body |
| signals along the nerve pathways. Previous | | | | connection is quite clear," reports Zubieta. |
| studies have shown that the brain responds | | | | |
| physically during the placebo effect, but the | | | | Suggestion Triggers Endorphin Release |
| new study is the first to pinpoint a specific | | | | |
| mechanism that triggers the brain's physical | | | | Another scan was performed in which subjects |
| response. | | | | were administered additional placebo prior to |
| | | | increased pain-induction to discern whether |
| "This deals another serious blow to the idea | | | | endorphin activity could be stimulated solely |
| that the placebo effect is a purely | | | | by suggestion. |
| psychological, not physical, phenomenon," | | | | |
| says lead author Jon-Kar Zubieta, MD, PhD, | | | | As additional placebo was administered, |
| associate professor of psychiatry and | | | | endorphin activity increased. Researchers |
| radiology at the U-M Medical School and | | | | then had to increase the amount of salt-water |
| associate research scientist at the Molecular | | | | in order to maintain the subjects' pain |
| and Behavioral Neurosciences Institute. | | | | levels, which they did without their |
| | | | knowledge. |
| The study involved 14 young men who agreed to | | | | |
| allow researchers to inject their jaw muscles | | | | Two-thirds of the study participants were |
| with a concentrated salt-water solution to | | | | classified as "high placebo responders," |
| induce pain. Brain scans were performed on | | | | experiencing significant endorphin activity |
| the subjects to monitor the activity of their | | | | through the power of suggestion. This helps |
| brains' natural painkilling endorphins during | | | | explain why so many people report relief |
| the process. | | | | after receiving therapies and remedies that |
| | | | provide no actual physical benefit. |
| Mind-Body Connection Clear | | | | |
| | | | This new information may lead to better use |
| During one scan, they were told they would | | | | of cognitive, or psychological, therapy for |
| receive a medicine (in fact, a placebo) that | | | | people with chronic pain, the authors |
| might relieve pain. Subjects reported a | | | | suggest. |
| lessening of pain after receiving the | | | | |
| placebo, and brain scans indicated increased | | | | Researchers used positron emission tomography |
| endorphin activity in four areas of the brain | | | | (PET) scans to determine exactly which part |
| known to be involved in the response to, and | | | | of the brain the endorphin activity |
| processing of, pain. | | | | originated from, cross-registering them with |
| | | | magnetic resonance imaging (MRI) scans for |
| Every fifteen seconds, the subjects were | | | | the purposes of accuracy. |