My psychologist that I am seeing at the moment has suggested to me that depression is when a person thinks about things on a extremely deep level when the situation they are in is unhealthy. I don't know about this....I always thought depression was much more complicated than this. She's a great help to me and everything but I'm not so sure on her deffinition of depression. I believe that depression is deep thinking...but it's deep thinking caused by a painful situation, experience or situation as well as a combination of other factors. It is subjective for each person. What do you think? What's your own deffinition?