My spiritual father once told me that depression is a result of constantly living in the past (remembering wrongs done, mistakes made, bad experiences, etc...). It's a would have, should have state. Or it can be looking at the past as the "good old days" and misjudging the present moment through a skewed view of past and present. On the flip side he said that anxiety is a result of constantly living in the future (worrying about what might be or could be.) The remedy is to live in the present moment, and as this is the only thing that truly exists (the past is gone and the future is not promised to us), it's the only sane way to proceed. Of course, sanity is usually the most difficult route. :)
Thank you for sharing your thoughts and yourself!