Emotional Rollercoaster: A Journey Through the Science of Feelings. Claudia Hammond

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СКАЧАТЬ feelings about your status, which causes your serotonin levels to fall, with the result that you feel sad. Low serotonin levels tend to have different effects on men and women; women are more likely to become depressed while there’s some evidence that low serotonin levels in men lead to aggression. In the monkey studies it was found that after the dominant monkey had been removed, the serotonin levels of whichever monkey took its place would rise. Interestingly, if a monkey’s serotonin levels were artificially boosted, the monkey appeared to show an improvement in social skills and began rising through the group and, provided the dominant male was absent, could even take his place. If their levels were artificially lowered they would lose status.

      Trying this out on people, Alyson Bond gave them SSRIs for four weeks and then gave them various games to play as well as asking their flatmates to report back on any changes they might have noticed while living with them. During the games the people on SSRIs made more eye contact while they were speaking and less while the other person spoke – a sign of dominance. They also became more cooperative during the game, while their flatmates reported them to be less submissive than they used to be. This suggests that high levels of serotonin increased both their dominance and made them more cooperative. Although these two results might sound contradictory, in fact this fits in with the pattern seen in monkeys. Those of high status aren’t necessarily more aggressive, but they are better at getting on with other monkeys.

      So it appears that success can boost serotonin levels and high serotonin levels can lead to success, possibly through getting on with other people better, which might seem somewhat unfair. Those who are already happy and have high serotonin levels are likely to continue to succeed in society and remain happy, while those with lower levels – the very people for whom success could make a big difference – get left behind and their levels remain low. Most of the work in this area involves animals and so it can’t be guaranteed that the same effects would be seen in humans. However, a study conducted in Pittsburgh in 2000 found that the people with lower socio-economic status have a blunted response to a particular drug, which in turn suggests that they have a low turnover of serotonin. Since people with lower socioeconomic status are known on average to experience a greater number of stressful life events and to be exposed to more episodes of physical and psychological violence, the researchers speculate that these negative experiences could be altering the brain in such a way that the turnover of serotonin is reduced long-term.

      This illustrates that the search for chemical explanations does not rule out the role that life events can play in the way we feel. Our mood is not predicted solely by the quantities of certain chemicals in our brain. Changes in these chemicals might simply be a reflection of influences from outside, so when things go wrong in life the balance of chemicals can shift. Early experiences could even play a part by affecting the way in which the brain copes with changes in neurotransmitter levels.

      Earlier in this chapter the stress hormone Cortisol was mentioned. If it is the case that some depressed people have a problem with the system regulating Cortisol, then as with serotonin function the same question remains: why has the system gone wrong in those particular people? They might have been born with a predisposition to release excess Cortisol, or once again their experiences might actually alter the system. Charles Nemeroff from Emory University, Atlanta, has found that newborn rats who were separated from their mothers for ten out of the first twenty-one days of life, grew up with increased levels of the hormone. This suggests that early negative experiences might rewire the brain in terms of its response to stress. This hypothesis is based on animal studies, so is not entirely conclusive, but Nemeroff might have finally hit on a biochemical explanation for how bad childhood experiences could link to depression in adulthood.

      Not everyone believes that Cortisol or serotonin holds the chemical answers to depression. There is a new theory, admittedly very much in its infancy, that the immune system could be involved. The idea is that people with problems with the immune system respond in one of two ways – either they develop an auto-immune disease or they become depressed. Women are more prone to both of these conditions. It is even possible that drugs like SSRIs are acting not only on serotonin but on the immune system and the Cortisol system in addition, which could explain why the drugs take several weeks to have an effect.

      Again, these chemical changes in the brain could sometimes be a response to the outside world, rather than the brain spontaneously malfunctioning by itself. It’s arguable that we should no longer consider the physiological and the social to be separate. They affect each other, which would explain why drug treatments and talking therapies – which couldn’t be more different from each other – can both relieve depression.

      the mystery of tears

      Two years before her parents’ house burned down Julia was on holiday in Brisbane with her mother, who was recovering from cancer. Julia had recently called off her wedding and still felt desperately sad, but not wanting to add to her mother’s troubles she put on a brave face and tried to enjoy the holiday. Night-time provided the chance to cry. Once her mother was asleep she lay in the next bed weeping silently. Two weeks into the holiday her mother asked her why she was crying so often, admitting that she had listened to her sobbing every single night and didn’t want to be protected from Julia’s sadness just because she was ill.

      Julia was grieving for the loss of the future she’d imagined for herself and was keen not to add to another person’s distress by discussing it. These responses both make sense. What is stranger is that a clear liquid should fall out of her eyes because she’s unhappy. It’s easy to see how tears wash out your eye and protect the surface from a sharp speck of dust or an eyelash, but why do we cry when we’re upset? In physical terms a bout of sobbing blocks the nose, irritates the eyes, puffs up the face and makes the head ache, yet sometimes we can’t help but weep.

      A group of volunteers file into a makeshift cinema in a lecture theatre at the St Paul-Ramsey Medical Center in Minnesota, USA. They sit and watch a film about some children who are caring for their dying mother, only a year after their father died. It’s a film which openly manipulates the emotions. The phrase ‘tugging at the heart strings’ could have been invented for it. After they’ve lost both parents the children stand in a line in the snow while the eldest boy bravely declares that he will look after his young brothers and sisters. Meanwhile the heartless elders of the town just want rid of the lot of them. The volunteers watching the film have never met. They sit in silence wearing special goggles which have miniature buckets suspended beneath the eye-pieces. The reason they are here is to provide tears.

      After years spent studying crying Professor William Frey has found that this is the easiest way to make tears come forth. Unfortunately the special glasses didn’t work because tears escaped down the criers’ cheeks. In the end he found it was easiest to have people collect their own tears in tiny test tubes. He experimented with different films and seating arrangements, eventually concluding that spacing was the key. When people are close to a stranger they hold back the tears.

      Professor Frey went to all this trouble because he wanted to know whether tears of sadness contained different chemicals from the tears we cry when our eyes water due to soreness or irritation (known as irritant tears). He was drawn to the topic because he himself hadn’t cried since he was a boy and felt he might be missing out. Studies have shown that, like Professor Frey, some people don’t cry at all in a month, while it’s been found that others cry on up to twenty-nine days of the month. There are of course social rules prescribing when it is and isn’t appropriate to cry, particularly when it comes to boys. When my father was in pain in hospital after a tonsillectomy at the age of four, a nurse told him that boys don’t cry and that if he did people would think he was a girl. In fact despite this kind of social pressure, boys cry just as often as girls until the age of twelve, but by adulthood women are crying four times as often as men. Teenage girls are no more depressed than boys which has led to suggestions that the sudden difference in their crying frequency from the age of thirteen might be caused by the increase in girls in the hormones oestrogen and prolactin. However, СКАЧАТЬ