Science Focus - the home of BBC Science Focus Magazine
The deadly rise of depression © Getty Images

The deadly rise of depression

Published: 08th January, 2008 at 14:00
Subscribe to BBC Science Focus Magazine and get 6 issues for just £9.99

Depression is at its worst in Britain in the winter months. What can science tell us about this devastating mental illness? And what can be done to halt its escalation?

“Everything around me feels dark... I can hardly wake up, I go through the day in a complete fog... I can’t feel happy about anything... Nothing feels real, everything looks fake... I feel insignificant, like I am not even a person anymore... All I do is cry.”


These are descriptions written by people suffering from clinical depression. They will have felt this way for at least two weeks without let up, more likely for months. It’s a far cry from feeling a bit down for a day or two, which is what some of us might associate with feeling ‘depressed’. Real clinical depression is a life-threatening condition that plays havoc with your body as well as your mind, leaving you exhausted, unmotivated and sometimes suicidal. And the bad news is it’s on the rise the world over. The World Health Organisation has predicted that it will be the second most devastating disease in the world by 2020. In Britain, according to the Office for National Statistics, 10 per cent of the 60 million population is depressed, with numbers peaking in January and February when the added problem of Seasonal Affective Disorder (SAD) affects half a million of us.

So what’s causing this explosion of unhappiness? What is it about the modern age that is so mentally destructive? Probably the biggest factor is known as ‘westernisation’. In places where people still adhere to traditional lifestyles, rates of depression are incredibly low when it can be recorded. But as soon as these cultures are westernised, depression goes up. Why? Because people’s roles become less well-defined, relationships are more likely to break down, the workplace becomes more unpredictable and communities are more likely to fragment. There is also an unprecedented level of information and choice, which can lead to confusion. “Not knowing your place in society and having too much choice causes stress,” says Professor Ronald Duman of Yale University, a leading expert on the neurology of depression. “If you can’t cope with that stress, it can be a major factor in causing depression.”


Duman is one of several scientists who have made some startling discoveries in recent years about the effect that stress has on the brain. The first was made in the late 1990s when researchers from Washington University in St Louis studied the brain anatomy of 10 women who had suffered several bouts of major depression. They discovered that in the depressed women, stress had caused a reduction in size of up to 15 per cent in a brain region known as the hippocampus. Other studies revealed similar shrinkage in the prefrontal cortex, the brain area responsible for thought patterns. This blew apart the leading theory of depression that, for 40 years, had described the condition as simply being caused by low levels of neurotransmitters such as serotonin. “This new research showed that stress not only causes neurochemical changes but structural changes too,” says Duman.

Cell mates

The next major discovery was that the adult hippocampus can make new brain cells, a process known as neurogenesis. Previously, it was thought that when neurons died during adulthood, they could not be replaced. The discovery has led Duman and his colleagues to formulate a new theory of depression known as the neurotrophic theory. They hypothesise that stress decreases levels of a substance in the hippocampus and prefrontal cortex called brain-derived neurotrophic factor (BDNF). This chemical promotes nerve cell repair and growth, so a reduced level leads to deterioration of the hippocampus, causing depression.
This new understanding of the depressed brain has shed important light on how antidepressant drugs work. It was always a mystery as to why drugs such as Prozac, which is a selective serotonin re-uptake inhibitor (SSRI) that increases levels ofserotonin, took several weeks to work when it was known that it boosted serotonin levels within hours. The research done by Duman and others has shown that antidepressants work by increasing levels of BDNF, which in turn stimulates the birth of new cells in the hippocampus. The drugs take several weeks to lift the symptoms of depression because that is how long they take to induce neurogenesis – or new cell growth.
Now, the hunt is on for compounds that can target neurogenesis directly and therefore work faster. One unusual candidate that has made headlines within the last year is ketamine. Better known as a club drug – or a horse tranquilliser – it has been shown by researchers at the US National Institute of Mental Health (NIMH) in Bethesda, Maryland, to give relief from severe depression within hours. “This is very exciting,” says Duman. “The field has been trying to identify a rapid-acting antidepressant for decades and this research shows that it’s possible.”
In the meantime, while antidepressants can be a lifesaver for many people, they are far from a perfect treatment. Not only are they slow to kick in, taking between 10 days and six weeks, but for 20 per cent of patients they don’t work at all. For 70 per cent of sufferers the first drug tried doesn’t work. And when they do work, the risk of relapse is high.

Positive thinking

A growing armoury of psychological interventions can provide alternative or complementary treatments to antidepressants. One major approach is cognitive-behavioural therapy (CBT). This is an umbrella term for a range of psychotherapies that have as their central premise the idea that it is thoughts that cause feelings and behaviours, not external things such as people, events or situations. Relief is brought about by a change in negative thought patterns, so that they feel and act better even when the situation is the same. It is an approach that has been around since the 1950s, although many new branches of CBT have since been developed.
One recent addition to the CBT group is mindfulness-based cognitive therapy (MBCT) which uses meditation to help people who have suffered recurrent bouts of depression to stay well. “Meditation teaches you how to distance yourself from your thoughts so that when you say to yourself something like ‘I’m a failure, I’m a burden to everyone’ – the sort of thought that drives you down in a vicious spiral – you recognise that this is just thinking, it’s not necessarily true,” says Mark Williams, Professor of Clinical Psychology at Oxford University, and a co-founder of the MBCT programme. “People find it enormously liberating.”
Traditionally, the fields of neurophysiology and psychology have remained quite separate from each other in terms of the way they understand depression. However, the ideas of one British psychologist, Joe Griffin, have bridged the long-standing divide between the two disciplines and given rise to an exciting new therapy known as the Human Givens approach. It has sprung from 12 years of research into rapid eye movement (REM), the stage of sleep in which we do our dreaming. “It’s been known for 50 years that depressed people do more REM sleep, but why the sleep pattern was out of order like this wasn’t known,” says Griffin.

Dream machine

He describes dreaming as a mechanism by which the brain discharges unfulfilled emotional expectation or worry. Depression is caused by too much worrying and dreaming, which disturbs sleep patterns and leaves sufferers feeling continually exhausted, no matter how much sleep they have had. The first thing Human Givens therapists do with depressed patients is to explain this brain mechanism to them. They then teach them guided imagery (where their imaginations are guided towards a more relaxed state) and other techniques to help get their minds off worrying, so that normal sleep patterns can be restored. They explain the value of exercise because research has shown that exercise drives up serotonin levels, and serotonin blocks dreaming – leading to a more restful night’s sleep. “Depression is being generated on a 24-hour cycle and we can make a difference within 24 hours to how a person feels,” says Griffin.
Ultimately, neurologists and psychologists alike are agreed that the only long-term answer to the depression epidemic is to ensure that innate human needs are met. These include security, autonomy and control, privacy and a sense of competence. They are what Griffin means by the term ‘human givens’.
“If those givens are in place, people are mentally healthy,” he says. “But this is not understood by our politicians, by people running our health trusts.”
Surveys suggest that western nations are in danger of sacrificing human relationships, the main source of happiness, for economic growth. There is, however, a glimmer of hope – a new economics discipline known as Happiness Economics. This is a fast-growing field that describes the need for a country’s happiness to be tracked by indicators in the same way that its gross domestic product tracks its economic strength. It could be just the antidote needed in order to halt the deadly spread of depression.

Are You Depressed?

This is Goldberg’s depression test, developed in 1993 by American psychiatrist Dr Ivan Goldberg. The entries below refer to how you have felt and behaved over the past week – try to evaluate your condition in this time span only. Use the following scale to indicate the extent to which each statement is true by ticking a number, and add up your score at the end. If you suspect that you might suffer from depression, you should contact your doctor as quickly as possible, no matter what test result you get.

NB: The test result is not a final diagnosis and cannot replace professional help.

Not at all = 0
Slightly = 1
Partly = 2
Quite a lot = 3
A lot = 4
To a great extent = 5
  1. I do everything slowly
  2. My future seems hopeless
  3. I find it hard to concentrate when I read
  4. All joy and pleasure seem to have disappeared from my life
  5. I find it hard to make decisions
  6. I have lost interest in things that used to mean a lot to me
  7. I feel sad, depressed and unhappy
  8. I feel restless and cannot relax
  9. I feel tired
  10. I find it hard to do even trivial things
  11. I feel guilty and deserve to be punished
  12. I feel like a failure
  13. I feel empty – more dead than alive
  14. I have too little, too much or disturbed sleep
  15. I wonder HOW I could commit suicide
  16. I feel confined and imprisoned
  17. I feel down even when something good happens to me
  18. I have lost or gained weight without being on a diet
You do not have any obvious symptoms of depression. You seem to accept the ups and downs that are part of normal everyday life.
You have some symptoms of depression. Some of these symptoms normally occur in many people. It is difficult to say whether you will need treatment or not, but it is worth speaking to your doctor about how you feel.
You seem to have the symptoms of minor depression. Some of these symptoms normally occur in many people. It is difficult to say whether you will need treatment or not, but it is worth speaking to your doctor.
You have the symptoms of minor to moderate depression. These symptoms seem to cause a considerable amount of problems in your everyday life, and it would be advisable to consult a doctor.
You have the symptoms of moderate to severe depression. The condition seems to cause serious problems in your everyday life, and you should consult your doctor immediately.
You have the symptoms of severe depression. The condition seems to cause serious problems in your everyday life, and you should consult your doctor immediately.
While no replacement for professional diagnosis, Goldberg’s test is a way of helping to assess whether you have a problem with depression

Follow Science Focus on Twitter, Facebook, Instagram and Flipboard


Sponsored content