Depression is a common mental health problem – it affects nearly 1 in 6 people in the UK. The main symptoms of depression are losing pleasure in things that were once enjoyable and losing interest in other people and usual activities. A person with depression may also commonly experience some of the following: feeling tearful, irritable or tired most of the time, changes in appetite, and problems with sleep, concentration and memory.
People with depression typically have lots of negative thoughts and feelings of guilt and worthlessness; they often criticise themselves and lack confidence. Sometimes people with depression harm themselves, have thoughts about suicide, or may even attempt suicide. Occasionally a person with severe depression may have hallucinations and delusions. People with depression may have feelings of anxiety as well.
Depression may have no obvious cause, or it can be set off for a variety of reasons (such as physical illness, or difficult things that happened in the past or may be happening now, like bereavement, family problems or unemployment). Some people have what is called 'seasonal depression', which is linked to the change in seasons (usually occurring in winter when the days are shorter). People may have just one episode of depression. However, about half of people who have had an episode of depression will go on to have further episodes. Most people will feel better within 4 to 6 months of an episode of depression, while others experience symptoms for much longer.
The terms mild, moderate and severe depression are used in this information to describe different levels of depression.
Mild depression is when a person has a small number of symptoms that have a limited effect on their daily life.
Moderate depression is when a person has more symptoms that can make their daily life much more difficult than usual.
Severe depression is when a person has many symptoms that can make their daily life extremely difficult.
A person may experience different levels of depression at different times.
Healthcare professionals may use different terms for depression, such as 'major depressive disorder' or 'clinical depression'.
Sometimes a person has very few symptoms of depression that don't affect their life too much in the short term but can do if they continue for a long time – 'dysthymia' is a term that is sometimes used when a person has very few symptoms lasting for 2 years or more. Treatments for mild to moderate depression (see treatments for mild to moderate depression) may be helpful for people with very few symptoms that are persistent.