The intricate workings of the brain require a neurotransmitter called serotonin to function properly – too little leads to depression, too much causes unreal feelings of bliss
Laura Grant
DEPRESSION has been called the common cold of emotional life and Prozac, with worldwide sales of more than $2-billion and popped down the gullets of an estimated 20-million people, must surely be the psychotropic equivalent of aspirin.
Prozac (fluoxetine) was the first of a new generation of anti-depressants, which includes Zoloft (sertraline) and Paxil (paroxetine), that have had a marked effect on the way mental illness is treated. It’s not that these drugs are dramatically better than the preceding generation, tricyclics, in terms of efficacy, says Dr Michael Berk, associate professor of psychiatry at Wits University’s medical school. But they have fewer side-effects. (Interestingly, according to Berk, electroconvulsive therapy actually has a higher success rate in treating chronic depression – 80% to 85% compared to 60% to 65%. And, he notes, it doesn’t cause brain damage.)
However, these new treatments have helped to make the public aware that mental disorders, like depression, are really illnesses rather than personality flaws or failings. And that they can be treated neurochemically. At the same time, psychiatry has moved from lie-on- the-couch-and-tell-me-about-your-mother to “a hard scientific research-oriented discipline,” says Berk. “People are trying to find out what is going on in the brain that makes people ill.”
These anti-depressants work on a chemical in the brain called serotonin. It is a neurotransmitter, which means it sends impulses from one nerve cell to another, and, in simple terms, Prozac and its sister drugs act to increase the amount of serotonin available in the gaps between nerve cells (or synapses). They are known as selective serotonin reuptake inhibitors (SSRIs), which refers to the manner in which they influence serotonin. It is this that distinguishes them from other drugs which also affect serotonin.
Although serotonin is one of many neurotransmitters, it’s the flavour of the month in psychiatric research. “This is because it’s obviously intimately related to mood and anxiety. And most of the anti- depressants that we have work on serotonin, either directly or indirectly,” says Berk.
Serotonin is implicated in many illnesses besides depression. It plays a role in obsessive-compulsive disorder, where sufferers are plagued by obsessive thoughts, such as fear of contamination, and cannot stop themselves from, for example, compulsively washing their hands. Serotonin’s involvement has also been reported in obesity, bulimia, schizophrenia, suicide, sleep problems, migraines, premenstrual syndrome and anxiety attacks. SSRIs have even been prescribed to treat alcohol and nicotine addictions as well as gambling and compulsive shopping, according to a report in a US newspaper. Brain serotonin is also associated with something close to the heart of most South Africans, violent behaviour.
Dr Norbert Myslinski, associate professor of oral and craniofacial biological sciences at the University of Maryland in the United States, says that the link between low brain serotonin and violent behaviour is one of the most repeated findings in behaviour biochemistry. “Serotonin is an intrinsic part of the brain’s impulse control system. If we lose it, we lose control,” he wrote in the Baltimore Sun.
But violence associated with serotonin is impulsive, unpremeditated, occurs with minimal provocation and the offender usually doesn’t know the victim, says Myslinski. This rules out crimes motivated by economics. He admits, therefore, that neuroscientists cannot offer a cure for the majority of violence. But, he says, there are people who are chronically violent because of structural or chemical imbalances in their brains. “This is important because it is one of the causes of unpremeditated homicide, suicide and the abuse of spouses, children and animals.” And these people could be helped by drugs that manipulate brain serotonin.
Oliver James, author of a soon-to-be- released book entitled Britain on the Couch: A Treatment for the Low Serotonin Society takes things a step further. He claims our environment sets the level of our brain chemicals. Winning increases our levels of serotonin and losing has the opposite effect. So social “winners” have high levels of serotonin and, therefore, less serotonin- related mental illnesses. Low serotonin problems, he claims, are found in people with the lowest status. “Depression is most common among women with low incomes, violence most prevalent among their brothers, husbands and sons.”
Depression and violence, he says, “are caused to a large extent by feelings of subordination arising from being made to feel like a loser within families and the wider society”. So governments play an important part in determining the mental health of their citizens because by controlling the degrees of inequality, James says, they determine the serotonin levels.
Wits’s Michael Berk says this theory is too simplistic. It is the holy grail of psychiatry to find out how your behaviour is modulated by your biochemistry, he says. And we’re a long way from it. In any case most psychiatric disorders are fairly democratic, he adds.
“It doesn’t matter who you are. In fact, the evidence seems to suggest there are minor variations, but for the most part, wherever you are in the world, whatever race you belong to, whatever cultural group you belong to you’ve pretty much got the same risk of getting any illness. That’s much more striking a finding than a difference between class groups.”
Just because people suffering from some disorders can be made to feel better when their serotonin levels are adjusted it doesn’t mean that their problems are necessarily caused by serotonin. There are other factors at play. US psychiatrist Dr Edward Hallowell wrote in Psychology Today: “We are coming to understand that a complex interaction of genes, neurotransmitters, hormones, and the environment comes into play in mental illness.”
Unfortunately you cannot take two Prozac and go to bed when you’re feeling emotionally wobbly. Nor can we create a crime-free society by feeding SSRIs to criminals.
But chocaholics and those who eat when they’re down may have the right idea: there is a theory that a drop in serotonin levels leads to craving food high in carbohydrates, because these foods may help boost the amount of the neurotransmitter in the brain.
This kind of quick fix has unfortunate long- term effects – it’s far better just to exercise regularly. Exercise is a known mood-lifter, although its link with serotonin is still not understood.