The one time I got depressed was because of a career move away from my home and social circle. I used people (a lot) to fill that emptiness in my heart from starting my social life all over again... cutting corners socially is probably the best way to describe it. My depression was short lived... about 5 months. Eventually I snapped out of it when I started visiting family and true friends during vacation time.
The best advice I can give from personal experience is get in touch with family and friends.
Are you depressed because your wife left you? I can't give any advise on that unfortunately. I have a bad habit of not dwelling on people or girls when I'm through with them as cold as that sounds. Maybe that's advice within itself.
I am the black sheep 
"of course I'm crazy, but that doesn't mean I'm wrong."-Robert Anton Wilson
