What is the exact meaning of depression?

I think you have just come to understand why depression is so hard to cure. We can't even define it! There are so many different types and different symptoms that it is surely wrong to classify this as one illness.

I ever experiencing this condition. I feel like so scary and thinking often coz some one often bully me and i have to hold my breath. But thanks to internet, i now brave enough to against them. And my depression is gone

Depression according to the experts in that field is a mood disorder. It has been diagnosed as a disorder by itself like Major Depressive Disorder or as a co-factor within a disorder like "Adjustment Disorder with Depressed Mood." Depression can come about because of environmental factors such as a loss of a loved one, or as the result of a physical malady such as a chronic illness or serious infection. Of course it is normal to suffer depressed moods from time to time but the experts point out that when the depressed mood is experienced for a continuous period of time (2 weeks) or more, then a diagnosis of depression is suitable. Experts argue that depression is caused by changes in elements in the brain namely neurotransmitters. For more info check out this link. http://www.medterms.com/script/main/art.asp?articlekey=2947