You are onto something factoring social pressure. Social pressure has a direction, if a doctor says you are going to get better it is creating a pressure on yourself to get better. In many cases that pressure might be all you need.

The homeostasis effect might happen in an adversial situation. Say instead of a doctor, an opponent says something. It might cause to overcompensate in the opposite way. We could call that reverse placebo or by its more common name "spite".