On Brit TV this evening there was an interesting report on psychological side effects from medications. A clinical test was carried out involving a group of people who were given a pill to take each day and told it could cause muscular pain as a side effect. At the end of the trial 25% of the group had stopped taking the tablet because of muscular pains. The only problem was that the pill they had been given was a placebo - a sugar pill - which had no active ingredients whatsoever.
Another test was carried out with a different group only they were given a 50mg Vitamin C tablet, they were told it was vitamin C and were warned about the small possibility of a side effect. Once again 25% reported the non-existent side effect and many stopped taking it.
I blame resistance to medications on the leaflets that come with psychoactive medications which list yards of every side effect imaginable (it's a way that pharmaceutical companies cover themselves legally).
Such is the power of auto-suggestion.