Love Is the Best Painkiller

A new study carried out by the Stanford University School of Medicine found that passionate love provides the same effective pain relief as painkillers or illegal drugs like cocaine.

Sean Mackey, MD, PhD, chief of the Division of Pain Management, associate professor of anesthesia and senior author of the study says that “when people are in this passionate, all-consuming phase of love, there are significant alterations in their mood that are impacting their experience of pain.”

“We're beginning to tease apart some of these reward systems in the brain and how they influence pain.

“These are very deep, old systems in our brain that involve dopamine — a primary neurotransmitter that influences mood, reward and motivation,” he adds.

For studying the way that love alters pain, researchers recruited 15 Stanford University undergraduates – eight women and seven men, and asked every one to bring a photo of their loved one and another of an equally attractive friend.

They chose people who were in the first nine months of a relationship because they “wanted subjects who were feeling euphoric, energetic, obsessively thinking about their beloved, craving their presence.

"When passionate love is described like this, it in some ways sounds like an addiction, [s] we thought, 'Maybe this does involve similar brain systems as those involved in addictions which are heavily dopamine-related.'”

The experiment consisted in scientists successively flashing the pictures before the participants, while heating up a computer-controlled thermal stimulator placed in the palm of their hand, that caused moderate pain."

All this happened while the brains of the subjects were being scanned in a functional magnetic resonance imaging machine.

The participants were also tested for levels of pain relief while being distracted with word-association tasks like thinking of a sport that did not involve balls.

This last experience was carried out because previous studies showed that distraction causes pain relief, and the scientists wanted to make sure that love was not working the same way as a distraction.

The results showed that both distraction and love reduced pain, but they used very different brain paths to do so.

“With the distraction test, the brain pathways leading to pain relief were mostly cognitive,” said postdoctoral scholar Jarred Younger, PhD, now an assistant professor of anesthesia.

“The reduction of pain was associated with higher, cortical parts of the brain, [while] love-induced analgesia is much more associated with the reward centers.

“It appears to involve more primitive aspects of the brain, activating deep structures that may block pain at a spinal level — similar to how opioid analgesics work.

Younger added that “one of the key sites for love-induced analgesia is the nucleus accumbens, a key reward addiction center for opioids, cocaine and other drugs of abuse; the region tells the brain that you really need to keep doing this.”

This study does not imply that patients suffering from chronic pain should give up their painkillers and start a love affair, it's rather trying to better understand the neural-rewards pathways that get triggered by love, and explore new ways of producing pain relief.

To this study also took part Arthur Aron, PhD, a professor of psychology at State University of New York at Stony Brook and one of the authors, who had been studying love for 30 years.

He was actually one of the initiators of the study, several years ago after meeting Mackey at a neuroscience conference.

Some time later, Mackey, Aron and Younger set up the study that analyzed the brain images of undergrads 'in the first phase of intense love'.

“It turns out that the areas of the brain activated by intense love are the same areas that drugs use to reduce pain,” Aron said.

“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 study was published online October 13 in PLoS ONE.