Still crazy (in love) after all these years

WASHINGTON — New research on brain activity confirms that people can be madly in love with each other long after the honeymoon is over.

Researchers led by Bianca Acevedo at the Albert Einstein College of Medicine in New York wanted to know if romantic love — or at least the brain activity it triggers — could last in a long-term relationship. To everyone’s relief, the answer is yes. The group presented its results November 16 at the annual meeting of the Society for Neuroscience.

The new data suggest that people who have been madly in love for an average of 21 years maintain activation in a brain region associated with early-stage love. “We now have physiological evidence that romantic love can last,” says coauthor Helen Fisher, a biological anthropologist from Rutgers University in New Brunswick, N.J.

Most couples who have been together for many years experience a change from a frenetic, obsessive love to something more subdued and comfortable, says study coauthor Lucy Brown of Albert Einstein College of Medicine. But the researchers noticed a small group of outliers who had been with the same person many years and claimed to be as much in love as they were during the exciting early days of their relationship.

Since that earlier study in 2005 using functional MRI brain imaging, the researchers knew that a certain part of the brain called the ventral tegmental area was activated when people who had been in love for relatively short times — an average of seven months — saw pictures of their sweethearts. Perhaps not coincidentally, the ventral tegmental area is also activated by the rush of cocaine, and is the region that controls production of the natural stimulant dopamine. The researchers concluded that this area was associated with the intense, burning stages of early love. It was unclear whether this region would still be active after 20 years of being in a relationship.

Long-term lovers who had been married for an average of 21 years viewed a picture of their partner while the scientists monitored the subjects’ brain activity using fMRI. People who claimed to be madly in love for 20 years and people who had been in love only for months showed similar activation in the ventral tegmental area of the brain.

At the same time, key differences between the early- and late-stage lovers emerged that suggest potential benefits to staying together for 20 years. People in long-term relationships who were madly in love showed higher levels of activity in a part of the brain associated with calmness and pain suppression, whereas people in love for shorter periods of time had higher activity in a region of the brain associated with obsession and anxiety. “The difference is that in long term love, the obsession the mania, the anxiety has been replaced with calm,” Fisher said in a news conference.

“There is an evolutionary advantage to being paired,” says researcher J. Thomas Curtis, who studies pair-bonding in prairie voles, small animals that are well-known for forming life-long monogamous pairs. Much of the research on voles, including Curtis’ work at Oklahoma State University in Tulsa, Okla., supports these new findings on long-term pairing in humans, he says. In fact, when researchers get rid of the ventral tegmental area of a vole brain, the same region activated in human couples who are in love, the animal no longer forms pair bonds.

To understand the complicated subject of human love, the scientists plan to conduct more brain imaging studies. The next step will be to periodically monitor the brains of newlyweds as the couples slowly enter long-term relationships. The researchers hope to understand how brain activity may correlate with life events, like the birth of a child or relationship troubles, Acevedo says.