I have learning disability and was born premature. I weighted 1lb and 14 oz. and yes my mom smoked but she also has female issues her entire life. as far as concentration what i would do is do things in shifts. takes breaks. if you are having problems remembering something write it down and repeat it to yourself. some people learn visual , audio or kethastics. find out your best learning style. visuals and audio do well by reading and reading things out loud and kethics learn best by writting things down. i try to do all 3 when im trying to study. good luck