The science of the heart

KATHARINE ROSE'S father suffered a fatal heart attack when she was six years old. His mother, Menda, never got over the loss and, though she was a healthy 70-year-old, she took to her bed and didn't get up again. "She died six years after him," says Rose.

"The strange thing was that my grandfather Donald, who was also in his 70s, died just a week after her. He'd taken care of her during her last years, and they were devoted to each other. He'd been as fit as a fiddle until she died but his heart just gave way in his sleep without warning. We always thought he died of a broken heart."

The concept is nothing new. Last year, the parents of Spandau Ballet's Gary and Martin Kemp died within days of each other, while Johnny Cash died four months after his wife, June Carter, in 2003. Broken heart syndrome is a recognised condition, known as Takotsubo cardiomyopathy or stress cardiomyopathy. But because the symptoms are very like those of a heart attack, that is often recorded as the cause of death.

In 2007, a team from Glasgow University, led by the appropriately named Carole Hart, studied 4,000 couples and found that bereavement did indeed increase the risk of death for a partner left behind. Couples were aged between 45 and 64 when the study began, in the early 1970s, and researchers logged when each partner died. They found the bereaved had a 27 per cent higher risk of death from any cause in the six months after losing a partner than for those who still had their partners, and an even greater risk of heart disorders in the first five years.

But, says Professor Alexander Gardner, a chartered psychologist and psychotherapist based in Glasgow, this chain of events is by no means inevitable. "While people can die of a broken heart, it's if they let it," he says. "I think a sense of humour is a wonderful de-stresser – it takes you to a different place. It doesn't stop the grieving process but you go into it with a different perspective."

Dr Simone Meddle, senior lecturer in biomedical sciences at Edinburgh University and a specialist in how hormones affect behaviour, adds, "If your partner dies or leaves you, you feel loss. Being in love is very rewarding and very addictive, so when you remove that and break the partner bond, it will have consequences. Serious, life-changing incidences can cause depression."

The partner left behind can also take up unhealthy habits such as smoking or eating and drinking to excess. "These things replace the feeling you had when you were in love – you're looking for the same euphoria," says Meddle.

Others simply lose the will to live. "When you're with someone you have a reason for living, and if they suddenly disappear your purpose in life, particularly if you're older, might be gone."

But is there a physical explanation for what happens when we fall in love in the first place, or is it all in our heads? "When we are attracted to somebody – when we get the pounding heart, the quick breathing and sweaty palms – all that is caused by the release of adrenaline," says Meddle. "That's the first part of falling in love, when you have that craving for emotional union with that person."

Gardner adds, "Instant attraction can be compelling and sometimes obsessive. That butterfly feeling is based mostly on uncertainty because you're not clear about what the outcome will be. It's very common at the beginning of a relationship but in the long run you need something more. When romantic, butterfly love fades, you replace it with something else – the combination of passion, intimacy and commitment is what gives you a stable relationship. In a good marriage that lasts, you have all three."

That feeling of stability is caused by the release of what Meddle calls a "cuddle hormone" in the brain. "When you've fallen in love with somebody and formed those bonds, oxytocin is released. Its best-known function is its role in pregnancy – it causes the womb to contract during labour and for milk to be released when you're breast feeding. But during orgasm you also get a release of oxytocin, so that's thought to be partly important in terms of forming bonds.

"They've done experiments in prairie voles, which form monogamous relationships normally once they've had sexual interaction. But they can kick-start it by giving the female oxytocin. It acts on the same reward and reinforcement pathways in the brain as things like nicotine and cocaine – you get feelings of euphoria, and it's also addictive."

However, she says, scientists are still a long way from being able to explain exactly what goes on when we fall for someone. "We can make rodents form monogamous relationships but we're not sure if this is the same as understanding love itself."

Which is all very well for those in the midst of the great mystery of l'amour. But for some, it's a struggle to get their dream man or woman to even notice them. Fortunately, Gardner suggests it is possible to persuade someone to fall under your spell, with the aid of a little mirroring. "By imitating someone's posture you can make them feel more in union with you. So if the other person nods, you nod; if they cross their legs, you do the same. By doing that, the other person thinks, 'This person really likes me,' and when you feel liked, you're likely to reciprocate. Laughter, too, is a social engager. If somebody makes you laugh you're much more engaged by them."

Then, once you've snagged the object of your affections, surely you can do the same with the man on the street? "You can buy something called Liquid Trust," says Meddle. "It's based on oxytocin and you can squirt it up your nose. It has been used in studies to show it can induce trusting behaviour. It's like a love potion – you can manipulate the feelings of others with drugs."

However, she recommends the more traditional approach when it comes to showing you care. "I would say it was probably better to buy your partner flowers and chocolate, take them out for a romantic meal and hug and kiss them, because when you hug and kiss somebody this releases oxytocin – it's a natural stimulant."

Which goes to show that Roxy Music were right – love really is a drug. Here's hoping you score tonight.

• This article was first published in Scotland on Sunday, February 14, 2010