While the American Psychological Association doesn't define clear stages of depression, there does seem to be a pattern among the way that depression progresses among people. Here are the basic issues that may lead to depression in many people:
Feeling frustrated or overwhelmed – When life begins to become burdensome, you can begin to have troubles dealing with the emotions that come along with this anxiety
Sense of sadness at the way things are – Feeling like everything is out of control, you begin to feel sad and despondent.
Loss of interest in things you enjoy – You begin to isolate yourself from others and from the things you love to do.
Changes in eating and sleeping – You might begin to change the way you eat and the way you sleep as a way to cope with the burdens of your feelings.
Feelings of hopelessness – As you continue to feel bad, you might begin to see things as hopeless and beyond your control. You begin to not care about anything. You might stop bathing or handling even mundane tasks.
Feelings of death and suicide – Those who feel like they are completely alone and have no one to turn to will often begin to have thoughts of death and finally 'ending' it all.