[Paleopsych] Independent: Revealed: the chemistry of love

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Revealed: the chemistry of love
http://news.independent.co.uk/world/science_technology/article329619.ece

The good news: they've discovered the love chemical inside us all.
The bad news: it only lasts a year

The very source of love has been found. And is it that smouldering
look exchanged across a crowded room? Those limpid eyes into which
you feel you could gaze for ever? No. It's NGF, say unromantic
spoilsport scientists who have made the discovery, - that's short for
nerve growth factor.

And now, the really deflating news: its potent, life-enhancing,
brain-scrambling effect doesn't last. It subsides within the year of
first falling in love - presumably within the same period it takes
lovers to notice that the object of their affections can't get the
lid on the toothpaste.

"We have demonstrated for the first time that circulating levels of
NGF are elevated among subjects in love, suggesting an important role
for this molecule in the social chemistry of human beings," says Enzo
Emanuele of the University of Pavia in Italy.

Dr Emanueleand his researchers compared 58 men and women, aged 18 to
31, who had recently fallen in love with people in established
relationships and those who were single.

"Potential participants required to be truly, deeply and madly in
love," said the researchers. Only people whose relationships had
begun within six months were studied. The "in love" had to be
spending at least four hours a day thinking about their partner.

When the levels of blood chemicals were measured, it was found that
both men and women who had recently fallen in love showed very high
levels of NGF - 227 units compared with 123 units recorded in those
in long-lasting relationships. The study also found that those who
reported the most intense feelings had the highest NGF levels.

However, when researchers revisited people from the "in love" group
who were still in the same relationship more than a year later, the
levels of NGF had declined to the same levels as the established
relationship and singles groups.

Love is a neglected area of research and little work has been done on
its mechanisms. Dr Emanuele and his team believe they have conducted
the first investigation into the peripheral levels of neurotrophins
in people in love.

While the role of NGF in falling in love remains unclear, the
researchers suggest that some behavioural or psychological features
associated with falling in love could be related to the higher chemical 
levels.

"The raised NGF levels when falling in love could be related to
specific emotions typically associated with intense early-stage
romantic love, such as emotional dependency and euphoria," the researchers 
say.

"The specificity of NGF increase during early-stage love seems to
suggest that it could be involved in the formation of novel bonds,
whereas it does not appear to play a major role in their maintenance.''

Rocketing NGF, however, could be a necessary step on the way to an
enduring love because NGF is thought to play an important part in the
release of another chemical which plays a pivotal role in social bonding.

In a report about to be published in the journal
Psychoneuroendocrinology, the research team ends with a justification
for more love research that seemsquintessentially Italian: "Given the
complexity of the sentiment of romantic love, and its capacity to
exhilarate, arouse, disturb, and influence so profoundly our
behaviour, further investigations on the neurochemistry and
neuroendocrinology of this unique emotional state are warranted."