It does help a lot. If you take more than prescribed, it can become addictive. Having this disorder, taking twice the dose by accident is a rite of passage (early morning, you forget you've already taken it). After that, it became clear why they are Class B substances.
That aside, the change in my life has been tremendous. My manager didn't believe ADHD was worth exploring and was worried I would typecast myself, thus effecting my work. The opposite has been true - the change in my work has been a complete transformation.
I have recently gone through some events that have turned my life upside, though outside of my control. It's been 8 weeks and I'm amazed that I am coping so well. A fraction of this stress and chaos in my life was enough to lead me into a psychotic break when I was younger.