Clinical depression is quite a common condition and affects around 16% of the population at least one time in their lives, and it is described it as a situation that has got to the point of disruption to an individual's social life and/or their daily duties such as work and home life.

Clinical depression is found more in some Western countries like Australia where one in four women and one in six men will be found to suffer from it. It has been found that clinical depression is the main cause of disability in the US and the World Health Organization tell us that it is expected to become the secondary leading cause of disability in the world by 2020 after heart disease.

Clinical depression symptoms are varied and often include feelings and emotions that can be found in people without depression. Due to this health practitioners have to determine a proper diagnosis by applying a number of symptomatic criteria as suggested in the DSM-IV-TR or ICD-9/ICD-10.

The DSM-IV-TR criteria tells us for accurately diagnosing clinical depression, a person may be diagnosed as clinically depressed if he/she exhibits one of the following two elements for a period of two weeks or more:

A depressed mood or being unable to find pleasure from usually pleasurable events (otherwise known as Anhedonia).

Combining any of the two elements above with any five of the list of other symptoms experienced over the same two-week period is sufficient to diagnose clinical depression in a person:

* Being overwhelmed by feelings of sadness or fear

* Or inability to feel emotion (feeling empty)

* Finding less pleasure or interest in all, or almost all activities, even activities that they used to find pleasure in

* A changing of appetite and a noticeable affect either up or down in weight.

* Disruptive sleep patterns, which may cause insomnia, loss of REM sleep, or excessive sleep otherwise known as hypersomnia.

* Agitation affecting the psychomotor functions, or retardation

* Feeling drained, a mental or physical loss of energy.

* Feelings of guilt, helplessness, despair, anxiety or fear

* Trouble concentration or making decisions

* Slowing of cognition, including memory

* Recurrent thoughts of death or suicide including trying to kill oneself

A person can be diagnosed with clinical depression despite the fact that they do all of the criteria. As well as, the debate over the relative importance of genetic or environmental factors, or gross brain problems as against psychosocial functioning, is still currently ongoing.

Treating clinical depression may be different for each individual and that is important to remember. In fact, there are as many methods used to treat clinical depression as there are symptoms. Never the less, the two main methods used when treating the condition are usually medication and psychotherapy. In the event that medication fails, it is possible that a third treatment known as ECT or electroconvulsive therapy may be tried.