If the 40mg D,L Amphetamine (Adderall) we're talking about is extended release like the last 20mg, then I think you should be fine. For myself, this same dose really wouldn't do much. I would probably do at least double that to get a good buzz, but when you're naive to Amphetamines and stimulants in general, it can be harder to control yourself, especially the rate at which you talk or move your body/face/mout. You just might not be aware of how sped up you actually are, which can obviously be a problem.
If you can remain aware of how you are acting and can control it to a degree and your parents arent' already suspicious. Then you should be fine.
Unfortunately though, this type of thread really doesn't fit into the criteria for what is acceptable Basic Drug Discussion material. It's not a big deal becaue you're new, but I would encourage your to read the guidelines before creating more threads. Threads should ultimately revolve around the concept of Harm Reduction. Threads about how to get the most fucked up, acquire drugs, play doctors, fool parents, rob drug dealers, tell others how great drugs are and on and on, are not allowed, but are still frequently created.
Closed.