I think the learned helplessness experiment was something of a eureka moment of me. I see a direct analogy between dogs not escaping from pain and many work place scenarios... scenarios that lead to depression!

Corporate culture is particularly challenging in this regard... the individual can see so many problems but due to the in-agility/momentum of a large corporation, you often cannot affect change no matter how hard you try. Guess what the result is when you see no effect from repeated attempts? You become that dog in the cage that gives up, despite the stimulus (work place problems). You may recognize these people as the workplace cynic.

Given that you can't stop the pain, it makes sense to jump out of the cage that this point (get a new job!). Problem is the physiological damage of such a scenario actually limits an individuals ability to step back and see external opportunities etc.

A friend who works in the life coaching area mentioned Seligman recently and I completed his VIA Survey of Character Strengths and found it valuable. You might also like it. http://www.authentichappiness.sas.upenn.edu/Default.aspx

And here is a link that suggest activities that use your signature strengths in everyday life, which can improve life satisfaction. http://www.viacharacter.org/?TabId=132