Placebos

More interesting discussion of the placebo effect. Side effects that change with the drug being tested? Here is a good explanation on the possible source:

So, was the "nocebo effect" really making people feel worse? It could well have been, although there are other interpretations. People might just be more willing to report symptoms that they believe are drug side effects. Researchers might be more likely to write them down. And different kinds of people end up in trials of different drugs . . . Nevertheless, there's an important lesson here. Anecdotal evidence about drug's side effects shouldn't be accepted at face value, any more than anecdotes about their benefits. Drugs do, of course, cause adverse effects. But some drugs have worse reputations than they deserve in this regard. In such cases, nocebo effects might account for some of the reported problems.