AS summer days heat up, so do summer lovers. There they are, at the beach, in
the store, on the corner鈥攃ouples who stand so close and stare so longingly
that you blush just watching them. It鈥檚 love. It鈥檚 perfect, sweet鈥攁nd 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鈥攑eople who check and recheck the door to be sure it鈥檚
locked, or repeatedly try to wash away germs鈥擮CD 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鈥檚 thrills do indeed resemble OCD鈥檚 angst, both in outward habits and the
brain鈥檚 inner chemistry. Love is just a lot more fun. What鈥檚 more, these
researchers say, the pathology of romance may play a pivotal role in our
evolution. Their ideas are raising eyebrows鈥攁nd causing a few
giggles鈥攁mong 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鈥攁 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鈥檚 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鈥攁iding clotting鈥攂ut 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鈥攂ut 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鈥檚 more, both groups often know
their obsessions are somehow irrational, yet they can鈥檛 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鈥檚 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 鈥渘ormal鈥� 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.
鈥淚t鈥檚 often said that when you鈥檙e in love, you鈥檙e a little bit crazy,鈥� Marazziti
says. 鈥淭hat may be true.鈥�
To confirm their hunch that serotonin plummets solely during love鈥檚 first
flush鈥攁nd not later on鈥攖he researchers retested six of the original
20 in-love students a year hence. Sure enough, the students鈥� 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
鈥渆vening out鈥� 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鈥攁nd wondering whether this is a tentative first step towards
some interesting conclusions about life and love. 鈥淏ravo!鈥� says Thomas Insel,
director of Emory University鈥檚 Yerkes Regional Primate Research Center in
Atlanta. 鈥淎s scientists, we鈥檙e very quick to study stress, aggression, or grief,
but what of love? Why shouldn鈥檛 we know about this emotion, too? Any of us who
have fallen in love know that this is a profoundly biological process. Now
somebody鈥檚 actually trying to understand how.鈥�
Some scientists wonder what they鈥檝e been missing all these years. 鈥淔our hours
a day!鈥� marvels Yvette Sheline, a psychiatrist at Washington University in St
Louis. 鈥淲ho spends four hours a day thinking about someone?鈥�
The new findings may explain some quirks of human behaviour, too鈥攕uch
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鈥攃reating 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鈥攊mpulse stealing,
shopping and gambling鈥攂ring 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鈥檇 been and who she鈥檇
seen. He also insisted that she keep all windows in the house covered and go to
the beach fully dressed, so that strangers couldn鈥檛 sneak a peek. Hollander gave
this patient and five others Prozac-like drugs to enhance serotonin levels.
After treatment, the man鈥攚ho also had classic OCD checking
compulsions鈥攔elaxed quite a bit. The lesson, Hollander says, is that
persistent, intrusive emotion鈥攚hether it is breathless love or nervous
jealousy鈥攃an arrive with OCD-like intensity.
To be sure, Marazziti鈥檚 new study is preliminary. Because platelet measures
simply estimate overall serotonin, they can鈥檛 pinpoint specific changes in the
brain. Moreover, the study is small, and the in-love participants are mostly
women鈥攖hough 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鈥檚 chemicals certainly merit a closer look. Our fate鈥攏ot to
mention that of our genes鈥攔ests, 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鈥檚 co-authors on the
new study. Without intense emotion, which typically creates an unrealistic image
of the love object, rather like a photo that鈥檚 perfectly airbrushed, nobody in
their 鈥渞ight鈥� mind would fall in love, Akiskal says. By reeling you in and
stringing you along, making you believe that you鈥檝e caught the one
heart-stopping fish in the sea, the argument goes, serotonin keeps love鈥檚 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 鈥渟hort鈥� 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. 鈥淕enes don鈥檛 care
how crazy you are. They get passed on.鈥� Pausing a moment, Hamer adds: 鈥淲ell, if
you鈥檙e utterly crazy, it鈥檚 harder to find a mate鈥攁t least if you鈥檙e a
尘补濒别.鈥�
Love鈥檚 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鈥檚 inheritors may seek thrills in love, Akiskal says. But he thinks the
鈥済reat romantics鈥� are people suffering from cyclothymia, a bipolar disorder
somewhat like manic-depression, that brings alternating periods of intense
excitement and gloom.
According to Akiskal鈥檚 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鈥檚 dark side鈥攁nd 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鈥檚 not romance鈥攂ut a deeper attachment鈥攖hat
convinces parents to jointly care for their cute bundle of genes.
Ah, but then love comes full circle, at least in the animal kingdom.
快猫短视频s regard prairie voles鈥攆at little rodents rather like
squirrels鈥攁s nature鈥檚 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?