Most of us will probably have an ample amount of sadness in our lives, though probably not to a degree that warrants the diagnosis of depression. However there are moves to broaden the clinical definition.
|Depressed by Sander van der Wel|
In the UK 10% of people will be diagnosed with depression at some point in their lives, and internationally this rate varies from 3% in Japan to 17% in the USA.
What are the symptoms?
A formal diagnosis of depressive disorder requires the presence of five of the following symptoms for at least two weeks, one of which must be either depressed mood or loss of interest and pleasure:
- Sad, depressed mood.
- Loss of interest and pleasure in usual activities.
- Difficulties in sleeping.
- Poor appetite and weight loss, or increased appetite and weight gain.
- Loss of energy.
- Feelings of worthlessness and guilt.
- Difficulty in concentrating.
- Recurrent thoughts of death or suicide.
Why do people get depressed?
The current biological model of depression suggests that the disorder relates to a malfunction of the neurotransmitter seratonin. This chemical is used by brain cells to communicate, and helps to controls mood, appetite and sleep. Chemical anti-depressant thereapies (e.g. Prozac) therefore try to boost levels of seratonin.
However, this explanation does not account for the varying worldwide prevalence of depression, nor can it explain why this neurotransmitter is faulty in the first place.
An alternative cognitive view is that some people develop faulty thinking styles, sets of negative 'schemas' about themselves, the world and the future (Beck, 1976). These are self-reinforcing and lead to negative mood and loss of motivation.
The answer may lie in a combination of the two approaches, as both drug and cognitive therapies have been found to be effective for depression. Reconciling the different approaches in psychology is an important challenge, not least in mental health.
Beck, A. (1976). Cognitive therapy and the emotional disorders. New York: International Universities Press.
Davidson, G. and Neale, S. (2001). Abnormal Psychology (8th Ed.) New York: Wiley.