This BBC article talks about how some people are using amphetamines like Adderall and Ritalin to stay focused and motivated in high pressure jobs. It clearly works, at least for short periods of time. It is not clear whether it can work longer term, because people may either need a significant recovery period to recover from use of the drugs, during which they are less focused and motivated than normal, or else they may become addicted to the drugs. But the article also points out that the new drugs are not qualitatively different from using coffee to stay focused and productive – it is just a matter of differences in degree and chemistry, and coffee has proven to be safe and even beneficial to most people.