It seems sad that the filmmakers apparently have totally bought into the concept that life is "better through chemistry." I've noticed that a number of reviewers have missed the message, still labeling it a "cautionary film" despite the way in which Eddie winds up. If it were, the title would be ironic, but the ending shows that the filmmakers have no such intention.
After the credits rolled, I was reminded of the arguments of Timothy Leary and his followers about the higher consciousness gained from LSD and other psychodelic drugs back in the Sixties. A lot of people were seduced into taking a short cut to a promised "higher consciousness" through LSD and other drugs derived from sacred mushrooms. A lot of people paid a high price, levied on themselves and their families. Flawed though it be, Limitless does offer a good opportunity for a group to examine and debate its premise. In the light of the biblical witness, are we humans potentially limlitless? And do we know the difference between knowledge and wisdom?