What is depression?

The word depressed is a common everyday word. People might say "I'm depressed" when in fact they mean "I'm fed up because I've had a row, or failed an exam, or lost my job", etc. These ups and downs of life are common and normal. Most people recover quite quickly. With true depression, you have a low mood and other symptoms each day for at least two weeks. Symptoms can also become severe enough to interfere with normal day-to-day activities.

What are the symptoms of depression?

Many people know when they are depressed. However, some people do not realise when they are depressed. They may know that they are not right and are not functioning well but don't know why. Some people think that they have a physical illness - for example, if they lose weight.

There is a set of symptoms that are associated with depression and help to clarify the diagnosis. These are:

Core (Key) Symptoms

Persistent sadness or low mood. This may be with or without weepiness.
Marked loss of interest or pleasure in activities, even for activities that you normally enjoy.

Other common symptoms

Disturbed sleep compared with your usual pattern. This may be difficulty in getting off to sleep, or waking early and being unable to get back to sleep. Sometimes it is sleeping too much.
Change in appetite. This is often a poor appetite and weight loss. Sometimes the reverse happens with comfort eating and weight gain.
Tiredness (fatigue) or loss of energy.
Agitation or slowing of movements.
Poor concentration or indecisiveness. For example, you may find it difficult to read, work, etc. Even simple tasks can seem difficult.
Feelings of worthlessness, or excessive or inappropriate guilt.
Recurrent thoughts of death. This is not usually a fear of death, more a preoccupation with death and dying. For some people despairing thoughts such as "life's not worth living" or "I don't care if I don't wake up" are common. Sometimes these thoughts progress into thoughts and even plans for suicide.

An episode of depression is usually diagnosed if:

You have at least five out of the above nine symptoms, with at least one of these a core symptom; and:
Symptoms cause you distress or impair your normal functioning, such as affecting your work performance; and
Symptoms occur most of the time on most days and have lasted at least two weeks; and
The symptoms are not due to a medication side-effect, or to drug or alcohol misuse, or to a physical condition such as an underactive thyroid or pituitary gland. (However, see section later on depression and physical conditions.)

Many people with depression say that their symptoms are often worse first thing each day. Also, with depression, it is common to develop physical symptoms such as headaches, palpitations, chest pains and general aches. Some people consult a doctor at first because they have a physical symptom such as chest pains. They are concerned that they may have a physical problem such as a heart condition when it is actually due to depression. Depression is in fact quite a common cause of physical symptoms. But, the opposite (converse) is also true. That is, people with serious physical conditions are more likely than average to develop depression.

Some people with severe depression also develop delusions and/or hallucinations. These are called psychotic symptoms. A delusion is a false belief that a person has, and most people from the same culture would agree that it is wrong. For example, a belief that people are plotting to kill you or that there is a conspiracy about you. Hallucination means hearing, seeing, feeling, smelling, or tasting something that is not real.