According to a study, researchers can design a better clinical trial using "placebo effect" where many people can feel better with a fake treatment.
A study in the journal PLoS One defines patients with certain differences on a gene which is connected to discharge dopamine were more likely to respond to placebo effect. Dopamine is a chemical that affects emotions and feelings of happiness and pain. Such patients responded to a placebo version of acupuncture better than patients with different variations.
Kathryn Hall, PhD, a research fellow in the Division of General Medicine and Primary Care and member of the Program in Placebo Studies and Therapeutic Encounter (PiPS) at BIDMC explains the study's first author:
"There has been increasing evidence that the neurotransmitter dopamine is activated when people anticipate and respond to placebos. With this new research, we may now be able to use a person's genetic makeup to predict whether or not they will respond to a placebo."
The placebo is found to be most effective in people who show improvements with a treatment although it contains no active ingredients. During the study in the genetic placebo marker in the dopamine trail, catechol-O-methyltransferase (COMT) gene was brought into consideration.
"COMT made for an excellent candidate because it's been implicated in the cause and treatment of many conditions, including pain and Parkinson's disease," Hall said. "It's also been found in behavioral genetic models of reward responsiveness and confirmation bias, the tendency to confirm new information based on your beliefs."
Hall further explains the polymorphisms and the impact of methionine and valine. "People with two copies of met, the "met/mets," have three to four times more dopamine available in their prefrontal cortex [the brain area associated with cognition, personality expression, decision making and social behavior] than the people with two copies of val," Hall said.
Scientists also found that met/met individuals had a higher response to placebo effect that met/val or val/val.
