"i have been taking this medicine for over two years now and when i first started taking it it turned my life around.  i&#039;m a senior in high school now and a high honors student and i credit my success mostly to the medication. after taking the 70mg dose for a long amount of time i have noticed that the benefits of the pill have decreased.  now, the medicine wears off within five hours of taking it.  compared to before when it would last all day.  i do not feel as focused as i used to while taking it, i do not feel the loss of appetite anymore, and i am becoming more forgetful."