Intranasal application of hormone appears to enhance placebo response

The hormone oxytocin may mediate processes such as empathy, trust, and social learning. These are key elements of the patient-physician relationship, which is an important mediator of placebo responses, according to background information in a Research Letter appearing in the October 23/30 issue of JAMA. Simon Kessner, of the University Medical Center Hamburg-Eppendorf, Hamburg, Germany, and colleagues conducted a study to test whether oxytocin enhances the placebo response in an experimental placebo analgesia model.

Between January and September 2012, the researchers randomly assigned 80 healthy male volunteers to 40 IU of intranasal or saline. The researchers and participants were blinded to study drug identity. After 45 minutes, placebo analgesia was assessed using the following standard technique. Two identical inert ointments were applied to 2 sites on each participant's forearm. The ointments were described as an anesthetic that reduces pain (placebo) and an inert control cream (control). In the 15 minutes following application that the participant expected the anesthetic to take effect, the researchers calibrated the intensity at which a 20-second painful heat stimulus was perceived by each individual to rate as a 60 on a scale ranging from 0 (no pain) to 100 (unbearable pain). During the subsequent test phase, a series of 10 of those calibrated stimuli was applied to each of the 2 sites in randomized order. The primary outcome was the placebo analgesic response, defined as the reduction of perceived pain intensity on the placebo site compared with the control site in the oxytocin and saline groups.

Despite identical stimulation on both sites, the difference in pain ratings at the placebo and pain sites were greater in the oxytocin group than in the saline group due to lower ratings at the placebo site.

"To our knowledge, our study provides the first experimental evidence that responses can be pharmacologically enhanced by the application of intranasal oxytocin," the authors write. "Further studies are needed to replicate our findings in larger clinical populations, identify the underlying mechanisms, and explore moderating variables such as sex or aspects of patient-physician communication."

More information: DOI: 10.1001/jama.2013.277446

add to favorites email to friend print save as pdf

Related Stories

Placebo effects of different therapies not identical

Jul 31, 2013

Not all placebos are equal, and patients who respond to one placebo don't always respond to others, according to research published July 31 in the open access journal PLOS ONE by Jian Kong from Massachusetts General Hospit ...

Making the brain take notice of faces in autism

Aug 15, 2013

Difficulty in registering and responding to the facial expressions of other people is a hallmark of autism spectrum disorder (ASD). Relatedly, functional imaging studies have shown that individuals with ASD display altered ...

Recommended for you

WHO: Millions of Ebola vaccine doses ready in 2015

Oct 24, 2014

The World Health Organization says millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines will start being tested in March.

Added benefit of vedolizumab is not proven

Oct 23, 2014

Vedolizumab (trade name Entyvio) has been approved since May 2014 for patients with moderately to severely active Crohn disease or ulcerative colitis. In an early benefit assessment pursuant to the Act on the Reform of the ...

Seaweed menace may yield new medicines

Oct 22, 2014

An invasive seaweed clogging up British coasts could be a blessing in disguise. University of Greenwich scientists have won a cash award to turn it into valuable compounds which can lead to new, life-saving drugs.

User comments