Passionate love can soothe pain, literally, Stanford University researchers have found. It apparently activates the same dopamine-oriented centers of the brain that tune in to illicit drugs such as cocaine.
"These pain-relieving systems are linked to reward systems," said Dr. Sean Mackey, senior author of a paper appearing online Oct. 13 in PLoS One
. "Love engages these deep brain systems that are involved with reward and craving and similar systems involved in addiction."
"This gives us some insight into potential ways of further probing and ultimately translating that into treatment for pain," added Mackey, who is chief of the pain management division at Stanford University School of Medicine.
Co-researcher Prof Arthur Aron, a psychologist at State University of New York, said: 'It turns out the areas of the brain activated by intense love are the same areas that drugs use to reduce pain. Aron has been studying love for 30 years.
"When thinking about your beloved there is intense activation in the reward area of the brain - the same area that lights up when you take cocaine, the same area that lights up when you win a lot of money."
The concept for the study was sparked several years ago at a neuroscience conference when Prof Aron met Prof Mackey an expert in pain management.
Prof Mackey said: "'Art was talking about love. I was talking about pain. He was talking about the brain systems involved with love. I was talking about the brain systems involved with pain.
"We realised there was this tremendous overlapping system. We started wondering 'is it possible the two modulate each other?"'
The authors recruited 15 Stanford undergrads who were "wildly, recklessly in love," said Mackey, adding that the recruitment process took "only days."
"It was the easiest study I've ever recruited for," he said. "Within hours they were all banging on my door, 'Study us! Study us!' When you're in that kind of love, you want the world to know about it."
The besotted 7 men and 8 women, who were still in the newly smitten phase of their relationships, came to the study with a picture of their beloved.
Researchers flashed the picture of the beloved while inflicting pain with a handheld thermal probe. As a control, participants were asked to name every sport that doesn't involve a ball, a form of distraction, while also activating the probe.
"To our pleasant surprise, both love and distraction reduce pain to an equal amount and that was good because it more fully allowed us to compare them," Mackey explained.
The pain relief afforded by looking at the picture of the beloved seemed specific to that act -- when participants were asked to look at a picture of an equally attractive and familiar acquaintance, their pain levels did not recede.
Functional MRI imaging of the participants' brain also revealed that, "the brain systems involved in distraction are entirely different from those involved in love," Mackey said. "In distraction, there was a much higher level of the newer corticol systems involved with classic attention and distraction."
On the other hand, "in love, very primitive, reptilian brain systems that are classically involved with the reward systems that motivate our basic drives were involved," he said.
Although the students in this study were at an age when love is often in the air, Mackey believes the results would easily translate to older folks.
"This doesn't require you to be an undergraduate at a university to fall head-over-heels in love," he said. "Even older people can do that."
Nor would someone have to be in the initial throes of a love affair to benefit from love's soothing effect.
"This gave me a greater appreciation that, for a patient in chronic pain, being in a loving relationship may actually provide some analgesic benefit," Mackey said.
Scientific evidence has shown in the past that distraction causes pain relief - and the researchers wanted to make sure that love was not just working as a distraction from pain.
The results showed both love and distraction did equally reduce pain - and at much higher levels than by concentrating on the photo of the attractive acquaintance.
Jarred Younger, an assistant professor of anesthesia at Stanford University, said: 'With the distraction test the brain pathways leading to pain relief were mostly cognitive. The reduction of pain was associated with higher, cortical parts of the brain.
'Love-induced analgesia is much more associated with the reward centres. It appears to involve more primitive aspects of the brain, activating deep structures that may block pain at a spinal level - similar to how illegal drugs work.'
Dr. Joe Contreras, chair of pain and palliative care at Hackensack University Medical Center, New Jersey, suggests distraction might be a more accessible, but also more often ignored, remedy.
But Anna Ratka, professor and chair of pharmaceutical sciences at Texas A&M Health Science Center's Irma Lerma Rangel College of Pharmacy in Kingsville, inserted a note of caution.
"This is still very far from [being useful clinically]," she said. "In my opinion, this is just another demonstration of the fact that pain is an extremely complex phenomenon and it's heavily dependent on perception, and that is actually very different across people."