In my experience, the effects of Adderall, and probably most psychoactive medications, depends on the person. I know people who do well by it. My personal experience is that it has no effect on my ability to pay attention. For many years, I had been taking Ritalin. At some point I noticed that I became depressed about five hours after taking a dose. After mentioning this to the psychiatrist who was prescribing my meds, I was put on Adderall. The depression went away, but so did the effect on my attention span. I went back to Ritalin soon after, with a nearly full bottle of Adderall gracing my medicine cabinet.

Like many other people with ADD, I grew out of the dependence on the drug. IMHO the main purpose of these substances is to provide a temporary crutch which a person can use to adapt to the disorder. Once I left the University and entered a job that I found enjoyable, I realized that even the Ritalin was doing more harm than good and have since been amphetamine-free.