Brain enhancing drugs should not be used. There are many negative effects that can occur by taking these drugs including memory loss as well as permenant brain damage. I think that these drugs should be banned all together not used. They do much more harm then good and do not have many benefits.
If we banned "brain-enhancing drugs" then we would suddenly be without all anti-depressants, anti-psychotics and most painkillers. It would set back medicine about 100 years, if not more. Perhaps some brain-enhancing drugs should be illegal, but let's make that determination on a case-by-case basis after careful study instead of simply tossing everything into the bin.