The point is, there are many things, including drugs, herbs, diet, mental health, social support, prayer, that are helpful and their helpfulness will vary not only due to their innate helpful qualities, but due to synergy (or lack of it, or even antagonism) with each other and with the inner environment (e.g. genetic limits) of the person receiving them. People used to understand how much medicine was an art of juggling variables. Now they expect something as cut-and-dried as changing the oil in a car--but even that can be done "better" or "worse."