Placebo effect

The placebo effect is oft misunderstood.  Strictly speaking, the placebo effect is the subjective or objective improvement in a patient's health after being administered a deliberately inert treatment which they believed would genuinely benefit them.  The label tends to get stuck on any number of unrelated though equally baffling phenomena.  Here's a few examples of similar effect which are in fact not placebo effects:

The nocebo effect. This is the subjective or objective deterioration in a patient's health after being administered a deliberately inert treatment which they believed would genuinely harm them.

The albedo effect.  This is the subjective or objective improvement of a patient's surface reflectivity after being adminisered a deliberately inert treament which they believed would genuinely make them more shiny.

The gazebo effect. This is the subjective or objective transformation of the patient into an outdoor, open-walled roofed area, usually octagonal, after being administered a deliberately inert treatment which they believed was a psychedelic drug.

The Placido effect.  This is the subjective or objective improvement in a patient's singing voice, particularly in the tenor range, after being administered a deliberately inert treatment which they believed was a gift from the Aoedean muse.

The libido effect.  This is the subjective or objective improvement in a patient's sexual drive or endurance after being administered a deliberately inert treatment which they believed was an aphrodisiac.

The bushido effect.  This is the subjective or objective improvement in the patient's ability to temper his violent martial instincts with forebearance, serenity and insight, after being administered a deliberately inert treatment which they believed was prescribed by the long-dead Japanese author and diplomat Nitobe Inazo. To be honest, it doesn't really come up that often but I thought I'd include it for completeness.

So the next time you go to your doctor complaining of having changed into a pavilion, belvedere, rotunda or pergola while you were tripping, and he mistakenly suggests that perhaps it was due to the placebo effect, you'll know precisely what to say!