Depression has been called the 'common cold of psychiatry' because it is the most frequently encountered mental illness. ivillage has linked with the mental health charity SANE to bring you the facts

Everybody gets 'depressed' from time to time but there is a huge difference between feeling a little low for a couple of days, and depression. When you are feeling low, you can usually find something that will cheer you up, whether telephoning or seeing a friend, or just treating yourself with your favourite food - or a long, hot soak in a bath.

The illness is another matter. True depression is a low mood that can last for a very long time and can actually affect the way you live your life - and the way you treat others. Most people suffer low spirits when things keep going wrong but, though they may be temporarily depressed, they recover quickly. This brief taste of depression is very different from depressive illness, which is long term and severe and needs professional help to treat.

Many doctors now believe that depressive illness is caused by some fault in brain chemistry, which makes sufferers predisposed to the condition. The illness may then be triggered by stress, physical illness, drug abuse and the like. There are no laboratory tests for depression so doctors can only diagnose from the patient's behaviour.

Depressive illness is very common although there are no reliable figures. The picture is that of an iceberg: the small part above the water represents cases that have been diagnosed; the great bulk beneath the water represents depressed people who have not sought help.

Britain, the Royal College of Psychiatrists says that 5 per cent of adults suffers from depressive illness at any one time.

Symptoms

The symptoms of a depressive disorder are a mixture of mood changes and despair with anxiety and physical problems. Anxiety may result in loss of appetite and weight, constipation, decline in sexual interest, headaches, sleeplessness, loss of energy and tiredness.

People suffering from depression can sometimes feel suicidal. Suicide threats should be taken seriously: about 70 per cent of the 4000 suicides a year in Britain are people suffering from depression and 15 per cent of all depressives eventually commit suicide.

Different types of depression

At the end of a period of depressive illness most people gradually recover their normal behaviour and, although the illness sometimes recurs, are effectively cured. This type of depression is called unipolar. But about one person in ten with depressive illness finds that when the depression lifts, they overshoot their normal state and enter a period of elation or mania.

This illness manic depression, affects about five people in 1000. Perhaps double this number show manic depressive tendencies. Unlike unipolar depression, manic depression is a psychotic illness and often causes bizarre behaviour.

Reasons for depression

People who have experienced recent adverse or traumatic events such as the loss of a job, bereavement, divorce, loss of money or status, rejection by a loved one or the need to care for small children under difficult circumstances, are at greater risk of becoming depressed. So are those who have experienced rejection in their childhood. Rejection in later life may then re-awaken the childhood feelings and lead to depression.

A variety of physical conditions may also lead to depression including infectious illnesses (such as influenza and glandular fever), medical treatment (such as chemotherapy and radiotherapy) and life-threatening or mutilating surgery. Neurological diseases such as Parkinson's disease, multiple sclerosis, stroke and epilepsy can all produce depression in their sufferers. So can cancer and kidney disease. Poor nutrition through an inadequate diet due to poverty or excessive dieting may also possibly increase the risk.

Women frequently develop depression after having a baby. Between 50 per cent and 80 per cent of mothers develop the 'blues' within a few days of giving birth. It is not usually serious and disappears within days.

True post-natal depression affects 5 per cent to 22 per cent of mothers and usually starts within six weeks of the birth. There is some evidence that social and psychological factors can make you more vulnerable to post-natal depression.

Even apart from post-natal depression, men are less likely than women to develop depressive illness. This may be due in part to changes in hormone levels which women experience during the menstrual cycle, menopause and during pregnancy.

Depressive illness is also common in old age, causing disruption of the sufferer's life and problems for carers. Elderly people may also be suffering from deficiency diseases such as anaemia, which may be the primary cause of the depression.

Some people suffer from an unusual form of depression called Seasonal Affective Disorder (SAD) which occurs only during winter and is due to lack of sunlight. It has been suggested that it may be caused by a rise in the level of melatonin, a substance produced in the pineal gland at the base of the brain, which causes animals to hibernate in winter. Production of melatonin is stopped if light levels are increased.

Treatment

It is important to recognise the early signs of depression and seek help before it gets any worse. If you think you, or someone you know well, might be suffering from depression, the important thing is not to ignore or hide away from the problem. You can get help, but first you must recognise there is a problem and talk to someone about it.

A variety of effective treatments for both unipolar depression and manic depression are now available.

Social treatments are aimed at helping to change the stress factors in your life and are therefore important to everyone suffering from depression. There are many different forms of counselling and psychotherapy which can help people to understand and cope with their illness. Many people with emotional disorders tend to have destructive and repetitive patterns of thought that prevent them from finding a way out of their difficulties. Cognitive therapy aims to recognise these negative thoughts and to try to counter them with alternative explanations that will break the loop.

For more information about psychological methods of treatment visit www.sane.org.uk

Antidepressants are very widely used in the treatment of moderate and severe depression, often in addition to counselling and social treatments. For more information about medical methods of treatment visit www.sane.org.uk

Lithium is used as a treatment for manic depression and works by controlling the major mood swings. Like all medication, lithium has side effects, the severity of which varies from person to person. People going on a course of lithium treatment should have kidney and thyroid function tests since water and salt balance are affected by the medication. During the course of the treatment, you will also need regular blood tests to check that the lithium level in the blood does not rise too high.

Help is always at hand

Don't try to cope with depression on your own. There is always help. You can turn to friends and family but, if you need other advice, your GP is a very good place to start. A GP can help you find the right type of treatment, referring you to a psychiatrist or community mental health centre, if necessary. The surgery will also hold a range of leaflets and information about local services.

Your local Community mental health centre will also offer a range of treatments once you have been referred by your GP. Most centres will carry out an initial assessment to identify your needs and highlight possible steps for managing depression.

Support from your family/carers

People with depressive illness can make those around them, particularly their family, feel depressed too. Dealing with mania can be even more frustrating and may also involve you in considerable difficulties. There are several things that can be done to help:

• Try to understand the condition
• Discuss the illness with the sufferer.
• Be affectionate and tolerant. There is enough self-blame and criticism in depressive illness without anyone adding to it.
• Reassure the sufferer. One of the major problems in depressive illness is the feeling of hopelessness.
• Cooperate with the treatment plan. If you have criticisms of it, discuss them with the doctor, not the patient.
• Summon professional help if the situation deteriorates.
• Consider joining a carers' support group in your area (Contact SANELINE for details of your local group).

For more information about depression visit www.sane.org.uk

For further help contact SANELINE www.sane.org.uk