AS summer days heat up, so do summer lovers. There they are, at the beach, in
the store, on the corner—couples who stand so close and stare so longingly
that you blush just watching them. It’s love. It’s perfect, sweet—and so
definitely sick.
Songwriters have long crooned that love is insane. But scientists now have a
more precise term for it: obsessive compulsive disorder (OCD). Made famous by
checkers and washers—people who check and recheck the door to be sure it’s
locked, or repeatedly try to wash away germs—OCD endlessly nags sufferers
with intrusive, anxious thoughts. Heeding these voices, people with OCD feel
compelled to repeat mundane activities or chase risky thrills, like
gambling.
That may not sound like blissful love, but some psychiatrists now say that
passion’s thrills do indeed resemble OCD’s angst, both in outward habits and the
brain’s inner chemistry. Love is just a lot more fun. What’s more, these
researchers say, the pathology of romance may play a pivotal role in our
evolution. Their ideas are raising eyebrows—and causing a few
giggles—among scientists. And their conclusions might just explain why
love makes you do such utterly foolish things.
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It all started in 1990, when Donatella Marazziti, a psychiatrist at the
University of Pisa in Italy, began looking for biochemical explanations for OCD.
One chief suspect was the neurotransmitter serotonin—a chemical that has a
soothing effect on the brain. Too little serotonin has been linked to
aggression, depression and anxiety; drugs in the Prozac family fight these
conditions by boosting the chemical’s presence in the brain. So Marazziti set
out to measure serotonin in people with OCD.
Tracking chemicals inside the brain is tricky, so she settled on a simpler
technique: calculating the amount of serotonin in platelets, tiny cells that are
easily retrieved from an ordinary blood sample. In blood platelets, serotonin
plays a totally different role—aiding clotting—but moves about in
much the same way as it does in the brain. Which means that scientists can gauge
roughly how much serotonin is skipping about your head from the levels of
related proteins in platelets. It may be an indirect measure, explains molecular
biologist Dean Hamer of the National Cancer Institute (NCI) near Washington
DC—but it can hint at how relevant the chemical is to different forms of
behaviour.
And, as Marazziti predicted, she found evidence that serotonin levels were
unusually low in people with OCD. But she also discovered something surprising.
Interviewing these patients, Marazziti was struck by the way their persistent
one-track thoughts mirrored the musings of people in love. Throughout the
day, both the people with OCD and the lovestruck can spend hours fixating on a
certain object or that certain someone. What’s more, both groups often know
their obsessions are somehow irrational, yet they can’t snap out of them.
Marazziti had to wonder, if serotonin dips dangerously low in OCD, could it be
doing the same when people fall in love?
To find out, Marazziti’s team went looking for love. They pinned
advertisements around the University of Pisa medical school asking for students
who had fallen in love within the past six months and who had obsessed about
their new love for at least four hours every day but who had not yet celebrated
the relationship with sex. They wanted to find Romeos and Juliets whose fresh
passion had neither been hormonally jumbled by sex nor dulled by time. Seventeen
women and three men with an average age of 24, signed up. Separately, the
scientists recruited 20 people who met the basic criteria for OCD and another 20
free from the grip of either love or psychiatric disorder.
Blood samples were taken from each member of each group, and then spun in a
centrifuge to separate out first the plasma and next the tiny platelets. While
the “normal” students had the usual level of serotonin, both the OCD and in-love
participants had about 40 per cent less of the chemical, as estimated by the
amount of activity of a serotonin transporter protein in their blood platelets.
“It’s often said that when you’re in love, you’re a little bit crazy,” Marazziti
says. “That may be true.”
To confirm their hunch that serotonin plummets solely during love’s first
flush—and not later on—the researchers retested six of the original
20 in-love students a year hence. Sure enough, the students’ serotonin levels
had bounced back to normal, while a more subtle affection for their partner had
replaced their original giddiness. According to previous studies, the same
“evening out” of emotion happens to OCD patients who take drugs that boost
serotonin levels to normal.
The offbeat study, just published in the journal Psychological
Medicine (vol 29, p 741, 1999), has researchers applauding,
chuckling—and wondering whether this is a tentative first step towards
some interesting conclusions about life and love. “Bravo!” says Thomas Insel,
director of Emory University’s Yerkes Regional Primate Research Center in
Atlanta. “As scientists, we’re very quick to study stress, aggression, or grief,
but what of love? Why shouldn’t we know about this emotion, too? Any of us who
have fallen in love know that this is a profoundly biological process. Now
somebody’s actually trying to understand how.”
Some scientists wonder what they’ve been missing all these years. “Four hours
a day!” marvels Yvette Sheline, a psychiatrist at Washington University in St
Louis. “Who spends four hours a day thinking about someone?”
The new findings may explain some quirks of human behaviour, too—such
as why we feel unusually passionate after downing a few pints. Abdulla Badawy, a
biochemist at Whitchurch Hospital in Cardiff, Wales, has shown that alcohol
seems to deplete serotonin in the brain, and that this chemical imbalance makes
some people quick to fight. Given the new study, Badawy speculates that
plummeting serotonin might also dissolve inhibitions—creating a passionate
haze that lures you into thinking that the person at the other end of the bar is
unbelievably attractive. So choose your bars carefully.
On a more serious note, scientists who study OCD say the comparison with new
love may be quite fitting. Eric Hollander, director of the Compulsive,
Impulsive, and Anxiety Disorders Program at Mount Sinai School of Medicine in
New York, says that while most people associate OCD with anxiety, it actually
represents a broad spectrum of conditions, some of which—impulse stealing,
shopping and gambling—bring a jolt of pleasure. Romantic love might fit in
here, he says.
Hollander has studied another heart-wrenching emotion affiliated with OCD:
obsessive jealousy. One of his patients was convinced that his wife was having
an affair. Every day, he quizzed his wife about where she’d been and who she’d
seen. He also insisted that she keep all windows in the house covered and go to
the beach fully dressed, so that strangers couldn’t sneak a peek. Hollander gave
this patient and five others Prozac-like drugs to enhance serotonin levels.
After treatment, the man—who also had classic OCD checking
compulsions—relaxed quite a bit. The lesson, Hollander says, is that
persistent, intrusive emotion—whether it is breathless love or nervous
jealousy—can arrive with OCD-like intensity.
To be sure, Marazziti’s new study is preliminary. Because platelet measures
simply estimate overall serotonin, they can’t pinpoint specific changes in the
brain. Moreover, the study is small, and the in-love participants are mostly
women—though men and women may process serotonin differently. Marazziti is
quick to call the research just a first step to understanding the biochemical
markers of love.
Image of perfection
Cupid’s chemicals certainly merit a closer look. Our fate—not to
mention that of our genes—rests, in part, on the firings of
neurotransmitters like serotonin, suggests Hagop Akiskal, a psychiatrist at the
University of California in San Diego and one of Marazziti’s co-authors on the
new study. Without intense emotion, which typically creates an unrealistic image
of the love object, rather like a photo that’s perfectly airbrushed, nobody in
their “right” mind would fall in love, Akiskal says. By reeling you in and
stringing you along, making you believe that you’ve caught the one
heart-stopping fish in the sea, the argument goes, serotonin keeps love’s fires
burning long enough for romance to yield an evolutionarily satisfactory end:
offspring.
For people with chronically low serotonin, in fact, life tends to be
unusually sexy. According to studies by Hamer at NCI and his colleagues, men
with a “short” version of the serotonin transporter gene, which results in
reduced serotonin, tend to be both more anxious and more sexually active than
those with a longer version of the gene. While these easy lovers keep the gene
pool going, they also litter it with neuroses, Hamer notes. “Genes don’t care
how crazy you are. They get passed on.” Pausing a moment, Hamer adds: “Well, if
you’re utterly crazy, it’s harder to find a mate—at least if you’re a
.”
Love’s chemistry can create other types of wildly passionate temperament,
too. In 1996, two teams of researchers traced novelty-seeking to a particular
polymorphism in the gene that encodes the D4 dopamine receptor. Some of the
gene’s inheritors may seek thrills in love, Akiskal says. But he thinks the
“great romantics” are people suffering from cyclothymia, a bipolar disorder
somewhat like manic-depression, that brings alternating periods of intense
excitement and gloom.
According to Akiskal’s research, people with cyclothymia fall in love during
happy times, often indiscriminately. This undiscerning pursuit of love creates
much mixing of genes in the sex that follows. However, Akiskal says, the
euphoria inevitably fades, as severe melancholy sets in, sometimes leading to
suicidal depression for the person with cyclothymia and potential danger for his
or her love interest. It is passion’s dark side—and researchers would
dearly love to understand the chemistry behind it.
When possible, scientists like to unravel biological mysteries with animal
models. But how do you make a rat fall in love? Geoffrey Miller, an evolutionary
psychologist at University College London, notes that while many species mate,
scientists have no clue how many actually feel romantic yearnings. After all,
once a baby is born, it’s not romance—but a deeper attachment—that
convinces parents to jointly care for their cute bundle of genes.
Ah, but then love comes full circle, at least in the animal kingdom.
Scientists regard prairie voles—fat little rodents rather like
squirrels—as nature’s ultimate significant other. Amid surging dopamine,
voles pledge lifelong monogamy to a partner. Perhaps, researchers reason, we
lovestruck humans can learn from these simple creatures. On the other hand, even
when a female vole is deprived of sex, yet given just a dose of dopamine, she
chooses any nearby male as her mate for life. Now, how sick is that?