My pdoc diagnosed me informally with depression and generalized anxiety, but he said that one aim of the therapy would be to find out which element was first. Then we found it was depression, and anxiety as a consequence. Lately we discovered a slightly bipolar pattern in depression, and this led to an improvement in the therapy. So I think that while many disturbs can be present at the same time, and symptoms overlap, it is always important to locate the biggest and primal problem, the one to be addressed with therapy.