My doctor started me on 20mg of Adderall XR once a day for ADD. I took it for the first time yesterday and I was surprised it worked so well. I was able to concentrate and had the energy/motivation to get my house clean, run errands, etc. It also put me in a great mood. I didn't feel depressed like usual. I did have some on the side effects like finding myself clenching my teeth and not much of an appetite which I was told could happen so not to worry. I took it this morning when I woke up and like yesterday, it seemed to take approximately two hours for me to feel it start working, but I don't feel as motivated or energized to do much. I feel it but it's as if it's not working like it did yesterday. Is this normal? Is it possible that it's not working the same because I took it at 2pm yesterday and this morning I took it around 8am? Could it be a tolerance issue? Or could my one 10mg valium that I take every night have effected how it works with me today? Thanks for your answers and thoughts in advance. Just thought I'd try to ask on here due to me not being able to speak with my doctor until after this weekend.