Previous studies show that a person’s strong belief in a drug’s performance can improve the effectiveness of the drug and vice versa if the person believes it to be ineffectual. This study evaluated a patient’s expectations of a pain reliever’s effectiveness or ineffectiveness against the actual relief of pain. Brain scans were used to check the success of the drug. Results showed that if a person expected benefit from the drug Remifentanil, the pain relieving capacity of the drug was doubled. Conversely, belief that the drug was ineffective actually eliminated the analgesic effect. Authors suggest, “that it may be necessary to integrate patients’ beliefs and expectations into drug treatment regimes alongside traditional considerations in order to optimize treatment outcomes.”
The success of drug therapy usually depends on the body’s response in terms of physiology. However, studies have shown that a person’s conviction of the benefit given by the drug can also have significant effects on the treatment outcome. Major drug trials on humans use placebo pills to compare with the trial medication. This is done to rule out perceived benefit and harm from actual benefit and harm caused by a drug. This study was conducted to evaluate whether such psychological factors can affect the pain relieving capacity of the painkiller Remifentanil. Researchers also attempted to understand the exact biology within the brain’s pain-processing areas when such psychological factors affect pain relief.
* For this study, 22 healthy volunteers were chosen. Constant heat pain was used as the pain stimulus.
* They were studied in three different situations. In the first condition, they did not expect pain relief with the medication. In the second situation, they expected pain relief and in the third condition, they expected their pain to be increased.
* All participants were given Remifentanil and their brain was scanned to see its response to pain stimulus.
* Each participant also noted their anxiety levels and perception of unpleasantness in questionnaires.
* Results showed that perception of pain intensity, as well as unpleasantness due to a painful stimulus, was reduced when the participants expected Remifentanil to be an effective pain reliever.
* It was seen that anxiety levels were also lower among those who thought the drug was actually working compared to the other groups.
* In the brain images, there was a significant decrease in pain-related brain images in the group that believed the drug was working. In the other groups, the brain images correlated with the pain intensity perception levels.
Authors agree that this experiment may not have similar implications in actual practice. They write that in real life, chronic pain sufferers have other pain modulating factors — like earlier experiences with the doctor, mood changes, etc. These factors may work alongside efficacy perception of the drug and change the way it acts. They add that their brain scans do not actually define the molecular level changes that their perceptions create and further studies could elaborate on this.
Authors write that this study proves that psychological factors, such as being aware about an administered drug, significantly affect treatment outcomes. This implies that drug trials on humans should be better designed to gain deeper insight. Since drug trials often use a placebo to compare with active drugs, these results may be of special importance. This study shows that placebos may also have some level of effectiveness and this may distort the findings with an actual drug. Better study design with these factors in mind is warranted. Authors also suggest that, “Understanding and controlling the psychological context in which medicines are delivered will be an important part of making” medicine personalized for an individual.
For More Information:
The Effect of Treatment Expectation on Drug Efficacy: Imaging the Analgesic Benefit of the Opioid Remifentanil
Publication Journal: Science Translational Medicine, February 2011
By Ulrike Bingel; Vishvarani Wanigasekera; University of Oxford, Englandand University Medical Center Hamburg-Eppendorf, Hamburg, Germany
*FYI Living Lab Reports Are Summaries of the Original Research.