Hi, I feel exactly the way you do. I think having a more complicated job (I'm an elementary teacher) makes it more difficult for me. There are so many factors to consider when planning and implimenting good instructional techniques, monitoring student progress, etc., that I get overwhelmed. If I spent as much time as I needed to really do the job justice, I would never go home! My roommate (who is studying to be a nurse) thought I might have dysthmia (mild depression). But like you, I don't know which leads to which. I suspect my ADD leads to my depression, and like you said, it becomes a vicious cycle.