The mind is powerful: it can build and destroy anything, including itself. The well-known placebo effect is a manifestation of its ability to build while the lesser known nocebo effect is a manifestation of its ability to destroy.  Example: a young man signed up for clinical tests of an experimental drug.  He was unknowingly selected for the control group, which received sugar pills.  Later, in a fit of depression, he swallowed the entire bottle of sugar pills intending to kill himself.  Although the…