The stigma to medication comes from the placebo being as effective as the actual medication on many cases. What you think will
work is most likely to
work let it be medication, psychotherapy, diet, exercise, social or whatever you think might work might just work. You can be conscious or unconscious of what you thing will work tho and I must admit that this is a problem.
We see the same thing happens in biology. See Bruce Lipton's the Biology of Beliefs.