David Murray, a professor at Reformed Puritan Theological Seminary, has written a wonderful little book. This does not claim to be an exhaustive analysis of depression, but it does give the reader an excellent insight into both the physical and spiritual causes, processes, thinking and treatment for depression / feeling low.
There are a ton of referenced resources in this book which will keep you reading for months if you so wished. Most of all Murray has struck just the right tone and weight with his discussion, balancing the theoretical with the practical. His wisdom, insight and pastoral experience makes this one of the best books I have read in a while. It does not matter whether you have or have had depression or not – this book is worth reading