Taken from Spiritual Depression by Dr. Martyn Lloyd-Jones.
“I suggest that we cross the line from self-examination to introspection when, in a sense, we do nothing but examine ourselves, and when such self-examination becomes the main and chief end of our life. We are meant to examine ourselves periodically, but if we are always doing it, always, as it were, putting our soul on a plate and dissecting it, that is introspection. And if we are always talking to people about ourselves and our problems and troubles, and if we are forever going to them with that kind of frown upon our face saying: I am in great difficulty–it probably means that we are all the time centered upon ourselves. That is introspection, and that in turn leads to the condition known as morbidity.”