Depression causes me to be completely lacking in the ability to concentrate. I feel dumb when I'm depressed. I have not been depressed all of my life, in fact, this has only been the way of life for me for about the past 9 months; so I know that when I'm not depressed, I function so much better in all areas (thinking and concentration included). I hope that it gets better for you soon. Oh, and medication hampered my ability to concentrate too...