Depression takes over the whole body - emotions, bodily functions, behaviours and thoughts but is most often described by the main symptom, low mood and sadness.

This sadness is a deep unrelenting pain that makes the person unbearably miserable and seemingly incapable of any joy or enthusiasm. In addition, many of those suffering with depression also report a loss of interest in life.


Emotional symptoms include sadness and depressed mood, loss of pleasure and interest in life and irritability. Apart from the emotional, bodily functions are also disrupted.

Changes can be seen in appetite, sleep and activity levels. Some people with depression lose their appetite and others want to eat more. Some can’t sleep and others want to sleep all day. Behaviourally many people with depression are slowed down (psychomotor retardation) in that they may walk more slowly, gesture slowly and talk more slowly and quietly.

A small number speed up (psychomotor agitation) and find it difficult to sit still and may move around and fidget aimlessly. Many have less energy and often report feeling chronically fatigued.

On a cognitive level the thoughts of people with depression can be filled with themes of worthlessness, guilt, hopelessness and even suicide. They often have trouble concentrating and making decisions and in very severe cases people can lose contact with reality.

Different Types of Depression

There are many types of depression and within the major types there are many subtypes. For example, unipolar depression encompasses Major Depression Disorder and Dysthymic Disorder. Within Major Depression there are 6 subtypes for other more specific depressions such as postpartum, catatonia or where psychotic features are present.

How Common is Depression?

Depression is one of the most common psychological problems and data from the USA suggests that 16% of people will have an episode of Major Depression in their lifetime. Within age groups, 15-24 year olds have the highest risk. The risk then decreases as we get older but rises again for those over 85. Women as twice as likely as men to experience both mild depressive symptoms and severe depressive disorders. This gender difference has been found in many countries across many age groups.

Good and Bad News

The good news is that once people undergo treatment for their depression they tend to recover much more quickly and the risk for relapse is reduced. The bad news in that many people with depression never seek treatment or else wait years, all the time suffering, before they seek help. Often this is because they feel that they should be able to get over their symptoms on their own or they feel that they are going through a phase that will pass with time and won’t affect their lives in the long term.

CBT is the most effective psychological treatment for depression and depending on the severity medication may or may not be indicated. The National Institute for Health and Care Excellence (NICE) issues guidelines for the most effective treatments for many medical and psychological conditions. These guidelines recommend CBT as the treatment of choice for Depression.