It seems that a positive attitude avoids illness, shown in an experiment by CMU (Pittsburg) psychologists:
his group exposed 334 healthy adults to one of two rhinoviruses via nasal drops. Those who displayed generally positive outlooks, including feelings of liveliness, cheerfulness, and being at ease, were least likely to develop cold symptoms.
All subjects started the experiment in basically good health, so the results weren’t being set up by choosing unhealthy, unhappy subjects. It seems that Bobby McFerrin was right when he sang “Don’t Worry, Be Happy”:
In every life we have some trouble
But when you worry you make it Double
...or, conversely — when you happy, its power you nubble? (-: