I did dexedrine and it works well. I would take 15mg 2 times a day, sometimes 20, if I didn't sleep very much. Sleep plays a big part in how the medication works (for me), if I sleep well, I notice the med the next day, if not, it just keeps me going and able to sit and continue working (my mind would still wander). It helped a lot in the long run for me, but it IS addictive. Make sure you take breaks every week because otherwise the withdrawal is not fun (very depressed, sleep for basically 3 days straight).