From Cuddle Chemical to Love Drug

Researchers are trying to harness the power of oxytocin.

By By Maia Szalavitz  / MSN Health and Fitness

When oxytocin is released in the brain, it increases trust, decreases anxiety and somehow helps joyously connect mother to baby—and lover to lover. No wonder it's often called the "cuddle chemical" or the "love drug."

New research suggests that drugs made to simulate oxytocin could be useful to treat everything from anxiety disorders to autism.

The stuff love is made of

Oxytocin is both a hormone and a neurotransmitter. During labor, it produces uterine contractions and later spurs the "letdown" of milk for nursing. In fact, many pregnant women are given a synthetic version during childbirth (Pitocin) to speed things along.

Anyone who has had this experience tends to be shocked when they hear that they were given the "love drug"—intensified contractions don't tend to inspire that emotion!

In the brain, oxytocin has very different actions than in the uterus.

Most famously, research on mouse-like voles has shown that it is involved in creating pair bonding.

In prairie voles, oxytocin seems to wire in a connection between one particular partner and pleasure (another chemical, vasopressin, is needed as well in males); prairie voles are monogamous creatures.

But promiscuous montane voles don’t have much of these crucial chemicals in their brain's pleasure areas—to them, any partner goes.

So, at least in voles, oxytocin and vasopressin are the stuff that love is made of.

There has been much speculation that humans taking oxytocin together would fall in love—but in experiments with hundreds of subjects, so far this hasn't happened, in either women or men.

Social connections

Oxytocin also seems to be involved in making social contact soothing.

"Oxytocin decreases anxiety," says Larry Young, Ph.D., Associate Professor of Psychiatry at Emory University School of Medicine. Ordinarily, he says, if you snap your fingers, a mother rat will jump, but "when nursing, she is very quiescent and relaxed. Women report the same kind of feeling."

So could giving oxytocin—or an analogue drug made to get to the brain more effectively—help with anxiety disorders?

The answer may well be yes. Two just-published studies support the idea that oxytocin helps people socialize.

The first study found that oxytocin decreased people's negative responses to images of faces which they had previously been taught to associate with bad feelings. There was reduced activation of the amygdala, a brain region associated with fear. This shows how oxytocin is involved in mending and sustaining social bonds. In the presence of oxytocin, it seems, you feel less bad about people you previously feared or disliked, allowing forgiveness and reconnection.

The other study involved brain imaging. It looked at people playing two version of a game. In one, they had to trust another person to divide up money; in the other version, the money was distributed by computer.

People given oxytocin continued to trust those who had previously betrayed them in the game, while those who were not given the drug showed decreased trust in that situation. The oxytocin didn't affect their reactions to the computer. While this shows that oxytocin could make people vulnerable, it also suggests that it could help with disorders in which people are excessively fearful and paranoid about others.

Finally, oxytocin shows some promise in helping treat autism, which also involves difficulty with social connections.

Research by Eric Hollander, MD, Chair of Psychiatry at Mount Sinai School of Medicine, has found that giving oxytocin intravenously to people with autism increases their ability to recognize and remember different emotional tones of voice, an important part of social skills.

Other studies found decreased repetitive behavior in autistic people given oxytocin.

Developing love drugs

Because natural oxytocin doesn't have very long-lasting effects, drugs with similar effects would need to be developed for treating autism, social anxiety disorders and depression—all of which involve both anxiety and difficulty with socializing and trust.

Not surprisingly, this is an intensely hot area of pharmaceutical research.

Luckily, there isn't much concern that oxytocin will be the next Oxycontin. Even though oxytocin's effects sound like those of a fabulous love potion, and would seem like a natural candidate for a recreational drug, so far most people who take it cannot distinguish it from a placebo. Why this is so remains mysterious. Whether a drug that gets into the brain better and lasts longer would be more addictive remains to be discovered.