Oh yeah. That's me...Being a depressive is not about being naturally depressed over events that have occured. As mentioned by others, depression is a good thing for certain occasions.
Being a depressive is having the feeling that everything is wrong and that something very bad is about to happen when there is no actual stimuli to cause such a feeling.
Feeling constantly anxious quickly causes the depressive person to become paranoid. Paranoia in turn can cause anger and aggression. A deeply depressed person can turn to being violent when to everyone else there is no evidence for a reason for violence.
Think about how you felt when you expected something that did not happen, or when someone you really loved spurned you, or when a relative or pet died prematurely. Take all of the things in life that may have caused you to have emotional pain, add fear so compelling that you know that any moment you are about to have something really bad happen to you, and then try to function while having all of these feelings constantly at the same time. That's chronic depression.
It may not be real, but it is reality to the person feeling it.