I once heard a lecture by Prof. Roy Baumeister of University of Queensland in which he described attempts to cure depression by improving the self-esteem of depressed individuals. The researchers thought that perhaps if the patients had a more accurate view of themselves, they would have a more positive mental state.

Unfortunately, they found that it was the non-depressed individuals who had an inaccurate view of their abilities and station in life! The depressed individuals seemed to view themselves quite accurately. So apparently, a bias towards evaluating yourself more positively seemed to play a role in inculcating positive mental states.

He said that instead of the much touted self-esteem, he now thought that perhaps we should focus on control and self-discipline. Overall an interesting idea, I thought.