I think it's not am easy process when dealing with depression, and it's because it completely has everything to with our emotions, emotions which can be influenced through certain events, situations and actions of people around us. But nevertheless, if a person puts their mind to it, they can easily overcome it with a lot of effort.
In order to overcome your depression, you need to know exactly what makes you depressed. Lets take for instance, a widow slipped into depression just few days after loosing her husband. Such a person can easily loose her depression state since we know sadness and the feeling of being lonely is the actual cause of her depression. She can begin the process by working on her emotions and letting go of the things that makes her sad.
However, not all cases of depression in people are as simple as that of the widow stated above. Some cases of depression are very complex to a point that the actual causes of such state of mind is unknown. Most of these type are people who surrferrd from years of abusive nurture or those born with a depression kind of sickness.