Depression is a very common illness.

According to the World Health Organisation, depression already represents the world’s 4th largest health problem and by 2020 will have moved up to 2nd place.

Doctors and other healthcare professionals believe that depression is caused by a change in the levels of certain chemicals in the brain.

Diagnosing depression

The term ‘depression’ is commonly used to describe a wide range of feelings relating to a person’s mood. However, the illness that a doctor or healthcare professional will diagnose as depression is different from ordinary sadness in that it can last for months, rather than just days or weeks, and is likely to have a profound effect on an individual’s life and their ability to function normally. Depression can make people feel hopeless about the future and, in severe cases, even make people think that life is not worth living.

Depression is often characterised by a range of different symptoms. These can include:

• Loss of interest in activities that the person would normally take pleasure in
• Low energy or fatigue
• Feelings of worthlessness and/or guilt
• Social withdrawal
• Inability to concentrate
• Difficulty sleeping
• Changes in appetite (eating more or less than normal, for example).

Depression can be triggered by various things, such as:

• Distressing events e.g. bereavement, relationship difficulties, redundancy
• Difficult circumstances e.g. stress or overwork, social isolation or exclusion, unemployment, poverty
• Illness - people with life-threatening illnesses, such as cancer or heart disease, or people suffering from chronic illnesses, such as rheumatoid arthritis and psoriasis, are also susceptible to depressive illness.
• Alcohol or drug misuse.

Depression can be treated in a number of different ways. The most common ways are counselling, cognitive behavioural therapy, and the use of anti-depressant drugs. Some people also find that complementary therapies can be useful.