By the late '90s, for example, the classic antianxiety drug diazepam (also known as Valium) was still beating placebo in France and Belgium. But when the drug was tested in the US, it was likely to fail. Conversely, Prozac performed better in America than it did in western Europe and South Africa. It was an unsettling prospect: FDA approval could hinge on where the company chose to conduct a trial.
Colours make a difference too. If you're looking for a pick-me-up then make sure you get the red placebo.
Also, I should really have heard of the "nocebo" before, despite finding that neologism quite ugly:
It also works in reverse to produce the placebo's evil twin, the nocebo effect. For example, men taking a commonly prescribed prostate drug who were informed that the medication may cause sexual dysfunction were twice as likely to become impotent.