[nroets]

Some meditation teachers concentrate on Buddhist teachings that's not part of mindfullness. They believe those teachings to be more important than mindfullness. If the experimentors ask one of those teachers to teach the patients to meditate, the meditation will be "fake".

[stone-monkey]

Can that really substitute as a placebo, though? I'd imagine you'd have to first verify that those teachings are no more effective than a placebo, which runs into the same problem as the original purpose of finding a proper placebo comparison.

Edit: Sorry, I misunderstood your comment. However, if they're testing the effectiveness of the meditation technique, then the teacher's belief in the method shouldn't affect the outcome of the result, assuming the technique is the same in both cases.