The causes of depression

If your parents or close relatives suffered from depression, there's a good chance that you could too. This isn't necessarily because the illness has genetic causes, though. It's more likely that growing up in a household with a depressed person can influence the perception that children have of the world, and shaking off that perception can be difficult.

Particularly in teenagers, and in women after childbirth, a change in hormone levels, coupled with a dramatic lifestyle change, can seriously increase the chances of depression.

If you expect to be a permanently-happy billionaire, footballer or supermodel, the chances are you're going to be disappointed. Setting impossibly high goals for yourself - or having them set by others - is a sure way to fall inexorably towards depression. This is an increasing problem because of the role models set by television and newspapers, which are usually distortions of the truth. Nobody's perfect, or even close. People who have trouble accepting that, especially in the workplace or at school/college/university, are prime candidates for depression.

Drugs and alcohol are not very good for the brain. Click here for more details.

Working from home is becoming increasingly popular in the UK, and it has its benefits; it usually allows people to get more work done than they otherwise would, with fewer distractions. But humans are gregarious, and need the company of others. If you spend nearly every day working from home, you'll miss out on important human interactions, and will be more likely to experience depression. E-mail and Internet chat are no substitutes.

Wake up early, get on a train, work hard all day, get on a train home, go to bed. That sort of lifestyle is going to cause problems, especially if the work ethic continues at weekends. All work and no play makes Jack a depressed boy, and stress just makes things worse. Relaxing and playing are important parts of life, and you ignore them at your peril.

Deeply traumatic experiences, like a car crash or the death of a close friend, can often lead to a period of grief or mourning. In some people, this can become prolonged and turn into depression.

This is similar to trauma, but at a different level. For example, if you've just come home from a fantastic six-month trip around the world, life will feel pretty mundane by comparison. This step down can lead to depression in some people.

Bottling up emotions after painful experiences, instead of expressing them and moving on, can cause problems in later life as those emotions resurface.

Seasonal affective disorder, or SAD, affects thousands and perhaps millions of people to a greater or lesser extent. Basically, it's the feeling of 'winter blues' associated with shorter days, less sunshine and grey skies. The symptoms are very similar to those of depression, and so winter can be a particularly bad time for depression sufferers. This effect is more common the further you go from the equator, which is one reason why suicide rates are high in Scandinavia.

Sitting at home all day in front of the television is bad for the body and the mind. People whose working day involves physical effort are less likely to suffer from depression.

The world is changing fast, and traditional roles no longer apply. Our lifestyles and the surrounding technology are evolving faster than we are, and sometimes this is hard for people to come to terms with, leading to a lack of purpose and the potential for depression.

Sometimes, there's just no apparent reason for the onset of depression. Perhaps a person's brain chemistry can just be thrown into a state of imbalance on its own, or perhaps there are many contributing factors - too subtle to be individually identified - that together become just too much to bear.