An illness that takes over completely as this one does of course can cause depression even while depression is not a part of this disease. It is a medical disease, not psychological as many have tried to make it out to be. However, the constant pain, the numerous losses in our lives, the doing our best to try and understand the disease and come to terms with it, and yet coming up short, all contribute to depression. Not having the best of medical care or even sometimes any at all, having to be our own doctor without the studies they went through, also contributes. It can't be helped, however, we can still learn to cope and we can use what tools we find available. The best solution for me has been the amino acid L-Theanine, for improving my mood. A nurse gave me that tip late, which I could have used much sooner.